A proposta deste trabalho é demonstrar a viabilidade de um sistema para inserção de um vídeo-avatar interativo em um ambiente virtual 3D, utilizando-se somente um computador pessoal e câmeras domésticas. Sua contribuição, em relação a trabalhos similares, consiste em integrar técnicas e algoritmos em uma solução inovadora de baixo custo computacional, voltada principalmente para aplicações de educação e entretenimento. Este trabalho expande as pesquisas realizadas anteriormente no Laboratório de Tecnologias Interativas sobre vídeo-avatares para teleconferência. O vídeo-avatar proposto é posicionado corretamente em relação a outros objetos do ambiente virtual e pode interagir com eles, sem a utilização de técnicas de reconstrução geométrica que apresentam altos custos de processamento. A demonstração da viabilidade da proposta é feita através da implementação de protótipos. / The proposal of this work is to demonstrate the feasibility of a system for the insertion of an interactive video avatar in a 3D virtual environment, using a single personal computer and home-use cameras. Its contribution, relative to similar works, consists in integrating techniques and algorithms in an innovative solution with low computational cost, aimed mainly at educational and entertainment applications. This work extends research previously performed at the Laboratório de Tecnologias Interativas about video avatars for teleconferencing. The proposed video avatar is correctly positioned in relation to other objects in the virtual environment and is capable of interacting with them, without resorting to geometric reconstruction techniques that present high processing costs. The demonstration of the feasibility of the proposal is performed through the implementation of prototypes.

Every smartphone today includes an accelerometer. An accelerometer works by detecting acceleration affecting the device, meaning it can be used to identify incidents such as collisions at a relatively high speed where large spikes of acceleration often occur.A gyroscope on the other hand is not as common as the accelerometer but it does exists in most newer phones. Gyroscopes can detect rotations around an arbitrary axis and as such can be used to detect critical rotations.This thesis work will present an algorithm for utilising the accelerometer and gyroscope in a smartphone to detect incidents occurring on a test track for cars. / Alla smarta telefoner innehåller idag en accelerometer. En accelerometer analyserar acceleration som påverkar enheten, vilket innebär att den kan användas för att detektera incidenter så som kollisioner vid relativt höga hastigheter där stora spikar avacceleration vanligtvis påträffas. Ett gyroskop däremot är inte lika vanlig som en accelerometer men finns i de flesta nyare telefoner. Ett gyroskop kan detektera rotationer runt en godtycklig axel och kan på så vis användas för att detektera kritiska rotationer. Detta examensarbete kommer att presentera en algoritm för att utnyttja accelerometern och gyroskopet i en telefon för att detektera incidenter som inträffar på en testbana för bilar.

This thesis describes methods for collision detection and collision response, implemented in a complete collision framework for both rigid and deformable bodies. The framework is intended to act as a base for new technologies regarding muscle and facial simulation for feature film production, at the visual effects studio MPC. Specifically, we implement sweep and prune as a first step in our collision detection for fast pruning of pairs, followed by optimized spatial hashing to decrease the amount of triangle intersection tests. Further, we use a constraint-based method for collision response based on iterative constraint anticipation, which provides several advantages in terms of accuracy compared to penalty- or impulse-based methods.

This paper describes our game engine written in C++, using the DirectX libraries for graphics, sound and input. Since the engine is written using DirectX, an introduction to this system is given. The report gives a description of the structure of the game and the game kernel. Following this is a description of the graphics engine and its core components. The main focus of the engine is on the physics and how it is used in the game to simulate reality. Input is discussed briefly, with examples to show how it relates to the physics engine. Implementation of audio in the game engine is not described, but a general description of how sound is used in games is given. A theory for the basics of how artificial intelligence can be used in the engine is presented. The system for the architecture of the levels is described as is its connection to the graphics engine. The last section of the report is an evaluation and suggestions for what to do in the future. A user manual for the level editor is included as an appendix.

This thesis treats how to generate collision information for multibody simulations in AgX Dynamicswhere the geometries are described with the data structure boundary representation, BREP. BREP is adata structure that contains the exact mathematical description of each individual surface. To describecomplex surfaces exact and efficient non uniform rational basis spline, NURBS, is used and for trivialsurfaces like planes or spheres simpler equations is used. Since all surfaces in a BREP is described veryaccurate, the accuracy for the collision information can be set high without affecting the amount of dataneeded to describe the geometries.To make AgX Dynamics able to calculate forces in a multibody simulation, collision informationabout were and how much two geometries are intersecting is required. The collision information containswere the overlap between two geometries is, how much the objects have penetrated each other and thedirection for which the objects have to separate. To find the penetration depth and the overlap theNewton Raphson method were used. The experiments conducted, showed that it is possible to useBREPs as a description of geometries to produce the collision information needed for the physics engineused by AgX Dynamics to handle collisions. A comparison between trimesh and BREP for producingthe collision information, shows that data usage is much lower for the representation of geometries withBREPs than trimesh. The results also shows that the accuracy can be significantly higher than fortrimesh as the data usage for trimesh becomes non practical to handle when the required accuracy ishigh. With the high accuracy and with the smooth surfaces used with the BREP the artificial friction isalmost negligible except for cases were intersection points could not be found all around the intersectioncurves due to limitations in the algorithm. / Detta examensarbete behandlar hur man skapar kollisionsinformation för flerkropps simuleringar i AgXDynamics där geometrier beskrivs med datastrukturen boundary representation, BREP. BREP är endatastruktur som innehåller den exakta matematiska beskrivningen för varje enskild yta. Att beskrivakomplexa ytor exakta och effektivt med non uniform rationell basis spline, NURBS, används och förtriviala ytor som plan eller sfärer kan enklare ekvationer används. Eftersom alla ytor i en BREP beskrivsexakt, kan noggrannheten för kollisions informationen sättas högt utan att påverka den mängd data sombehövs för att beskriva geometrier.För att göra AgX Dynamics kunna beräkna krafter i en flerkroppssimulering, krävs kollisions informationom var och hur mycket två geometrier kolliderar. Kollisions informationen innehåller varöverlappningen mellan två geometrier är, hur mycket objekten har penetrerat varandra och den riktningsom föremålen ska separeras. För att hitta penetrationsdjup och överlapp användes Newton Raphsonsmetod. De experiment som utförts, visade att det är möjligt att använda BREPs som en beskrivning avgeometrier för att producera kollisions information som behövs för att den fysikmotor som används avAGX Dynamics ska kunna hantera kollisioner. En jämförelse mellan trimesh och BREP för att producerakollisionen informationen, visar att dataanvändning är mycket lägre när geometrier representeras medBREPs än trimesh. Resultaten visar också att noggrannheten kan vara väsentligt högre för BREP änför trimesh eftersom dataanvändning för trimesh blir opraktiskt att hantera när noggrannheten är hög.Med hög noggrannhet och med de släta ytor som används med BREP blev den artificiella friction nästanförsumbar, utom i fallen där skärningspunkter inte kunde hittas runt hela skärningskurvor på grund avbegränsningar i algoritmen.

[EN] The efficiency of free-collision motion planning results very sensible on robot and obstacle modelling technique selected. In this way, many works have been oriented to define models with proper throughput to speed up the collision detection proccess. This dissertation presents a new approach to the problem, whose complexity is reduced notably by means of using enveloping models of real objects, allowing security regions or distances. This objective is reached by means of the definition of a spherical model, composed of infinite spheres, generated from the application of linear or polynomial equations to a reduced number of control spheres, giving the so-called poly-spheres and spheroids respectively. These models, with evident simplicity, present a high modelling power, adapt easily to the requirements need in collision-detection and path planning applications for robotics systems. In order to represent a complete multi-robot cell, an extended hierarchical structure has been defined, in form of an AND-OR graph, with different degrees of accuracy, according to the different approximation model used. In order to generate automatically this structure, a procedure has been developed to compute the minimum volume enveloping spherical model in an off-line process with two levels based on Downhill Simplex method and Hough transform. This procedure can be greatly speed up by using clustering techniques to obtain appropiate initial conditions, allowing an on-line use. With a hierarchical structure computed in such a way, a fast procedure for collision detection in a multi-robot cell is introduced, based on several algorithms for distance computation including polyspheres and spheroids. This methodology presents a fast and anticipativa response, in the sense that every movement of a system has been validated before its execution, implying that not necessarily must be done in an off-line simulation. The use of spherical models, in addition to their fast distance computation, results suitable for the definition of artificial potential fields allowing a path planning in robotics systems with up to six degrees of freedom, including three for translation and three for rotation. The definition of these new potential fields and the study of new planning techniques based on classical optimisation methods allow their application straight forward in Cartesian space, with all their advantages. Last but not least, with the help of some systems for robot programming, simulation and control, the correctness of these contributions have been validated in a set of prototype applications, covering from robot-obstacle and multi-robot collision detection, to motion planning for a robot-arm or an auto-guided vehicle. / [ES] La eficiencia de la planificación de movimientos libres de colisión resulta muy sensible al modelado de los robots y obstáculos que se consideren, por lo que, frente al modelado tradicional con politopos, muchos trabajos en robótica han estado orientados a la definición de unos modelos que presenten buenas prestaciones de cara a acelerar el proceso de detección de colisiones. En esta Tesis se presenta una nueva perspectiva del problema, cuya complejidad queda reducida notablemente al utilizar envolventes de los objetos reales, lo que permite definir zonas o distancias de seguridad. Para ello se han definido unos modelos esféricos, compuestos de infinitas esferas generadas a partir de la aplicación de unas relaciones lineales o polinómicas a un número reducido de esferas de control, dando lugar a las llamadas poli-esferas y esferoides respectivamente. Estos modelos, de sencillez clara, presentan una potencia de modelado elevada, adaptándose fácilmente a los requisitos necesarios en las aplicaciones de detección de colisiones y planificación de movimientos en sistemas robotizados. Para la representación de una célula multi-robot completa, se ha definido una estructura jerárquica extendida, en forma de grafo AND-OR, con diferentes grados de precisión, mediante diferentes modelos de aproximación. De cara a generar automáticamente esta estructura, se ha desarrollado un procedimiento para generar el modelo esférico envolvente de mínimo volumen en un proceso off-line con dos niveles, basados en el método de minimización Downhill Simplex y en la transformada de Hough. Este procedimiento se acelera enormemente al utilizar técnicas de agrupamiento para obtener condiciones iniciales apropiadas, permitiendo su uso on-line. Con una estructura jerárquica generada de esta forma, se introduce un procedimiento rápido de detección de colisiones aplicable a una célula multi-robot, basado en algoritmos básicos de cálculo de distancias que pueden considerar poli-esferas y esferoides. Esta metodología presenta una respuesta rápida y anticipativa, entendiendo por tal que todo movimiento de cualquier sistema ha sido validado antes de su ejecución, por lo que no necesariamente debe realizarse en una simulación off-line. La utilización de modelos esféricos, así como el rápido cálculo de distancias entre ellos, resulta idónea para la definición de campos potenciales artificiales que permitan una planificación de movimientos en sistemas robotizados con hasta seis grados de libertad, incluyendo tres de traslación y tres de rotación. La definición de estos nuevos campos potenciales y el estudio de nuevas técnicas de planificación basados en métodos clásicos de optimización permiten su aplicación directamente en el espacio cartesiano, con las claras ventajas que esto conlleva. Finalmente, con la ayuda de varios sistemas de programación, simulación y control de robots, se ha demostrado la validez de estas aportaciones en una serie de aplicaciones prototipo que van desde la detección de colisiones de un robot con un obstáculo o entre sistemas multi-robot, a la planificación de movimientos de un brazo-robot o un vehículo autoguiado. / Mellado Arteche, M. (1996). Modelado, detección de colisiones y planificación de movimientos en sistemas robotizados mediante volúmenes esféricos [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/56621

In present road traffic system, drone-network based traffic monitoring using the Internet of Vehicles (IoVs) is a promising solution. However, camera-based traffic monitoring does not collect complete data, cover all areas, provide quick medical services, or take vehicle follow-ups in case of an incident. Drone-based system helps to derive important information (such as commuter's behavior, traffic patterns, vehicle follow-ups) and sends this information to centralized or distributed authorities for making traffic diversions or necessary decisions as per laws. The present approaches fail to meet the requirements such as (i) collision free, (ii) drone navigation, and (iii) less computational and communicational overheads. This work has considered the collision-free drone-based movement strategies for road traffic monitoring using Software Defined Networking (SDN). The SDN controllable drone network results in lesser overhead over drones and provide efficient drone-device management. In simulation, two case studies are simulated using JaamSim simulator. Results show that the zones-based strategy covers a large area in few hours and consume 5 kWs to 25 kWs energy for 150 drones (Case study 1). Zone-less based strategies (case study-2) show that the energy consumption lies between 5 kWs to 18 kWs for 150 drones. Further, the use of SDN-based drones controller reduces the overhead over drone-network and increases the area coverage with a minimum of 1.2% and maximum of 2.6%. Simulation (using AnyLogic simulator) shows the 3D view of successful implementation of collision free strategies.

This thesis work investigated the advantages and disadvantages of using superquadrics (SQ) to do the collision-checking part of the Rapidly-exploring Random Trees (RRT) motion planning algorithm for higher Degree of Freedom (DoF) motion planning, comparing it with an established proximity querying method known as the Gilbert-Johnson-Keerthi (GJK) algorithm. In the RRT algorithm, collision detection is the main bottleneck, making this topic interesting to research. The SQ-based collision detection method was compared to the GJK algorithm both qualitatively and quantitatively, comparing computational speed, memory requirements, as well as the ability to handle arbitrary shapes. Furthermore, how appropriate they are in modelling a 6 DoF arm was analyzed. A qualitative comparison between the RRT algorithm and the A* algorithm was also provided, comparing their suitability for searching in higher dimensional spaces. When there were no collisions the SQ-based algorithms performed roughly at parity with the GJK algorithm in terms of computational speed. However, when a collision had occurred, the SQ-based algorithms were able to return a positive faster than the GJK algorithm, outperforming it. From a memory standpoint the SQ-based algorithms required less memory as they could leverage the explicit and implicit representations of the SQ objects, whereas the GJK algorithm requires both objects being checked for collision to be explicitly represented as convex sets of points. Regarding handling arbitrary shapes, the SQ-based algorithms have an advantage in that they can allow for certain non-convex shapes to be. Conversely, the GJK algorithm is limited to convex shapes. The GJK algorithm would thus require more geometric primitives to accurately capture the same non-convex shape. Thus, it can be concluded that the SQ-based method is more suitable for modelling a 6 DoF arm. However, a GJK-based collision detection module would in most cases be a lot more straightforward than the alternative to set up, as it is very simple to collect a set of points. Finally, both collision detection method types were implemented with the RRT algorithm. Due to the inherently random nature of the RRT algorithm the results of this set of tests could not be used to make any further conclusions beyond showing that it is possible to combine the SQbased algorithm with the RRT algorithm. Instead, one should see the RRT algorithm as a multiplicative factor applied to the inherent properties of the previously examined collision detection methods. / Detta examensarbete undersökte fördelarna och nackdelarna med att använda n:tegradsytor (NY) för att utföra kollisionsdetektion i algoritmen Raskt-utforskande Slumpmässiga Träd (RST). RST används typiskt för planeringen av system med relativt många frihetsgrader. En etablerad metod för kollisionsdetektion, Gilbert-Johnson-Keerthi-algoritmen (GJK), implementerades även i jämförelsesyfte. Då GJK-algoritmens största flaskhals ligger i kollisionsdetektionen är detta ett intressant ämne att efterforska. Den NY-baserade kollinsdetektionsmetoden jämfördes med den GJK-baserade metoden både kvantitativt och kvalitativt. Kvalitativt jämfördes beräkningshastighet och minnesåtagande, medan de kvalitativt jämfördes i deras förmåga att representera godtyckliga geometriska former. På ett högre plan diskuterades det även hur lämpliga de är för att modellera en robotarm med 6 stycken frihetsgrader. RST-algoritmen jämfördes även med en annan planeringsalgoritm, A*. Framförallt fokuserade diskussionen kring planering av system med relativt många frihetsgrader. I det fall inga kollisioner fanns presterade GJK-algoritmen ungefär lika bra som NY algoritmerna i att fastslå detta, utifrån beräkningshastighet. Men när det kom till att upptäcka existerande kollisioner presterade GJK-algoritmen sämre. Minnesmässigt använder GJK-algoritmen mer minne, då den kräver att båda objekten är explicitrepresenterade (dvs, som ett punktmoln), medan man med en NY-metod endast behöver representera ena objektet explicit och den andra implicit. Gällande förmågan att representera godtyckliga geometriska former är NY-baserade metoder bättre. Till skillnad från GJK som är begränsad till konvexa mängder kan NY uppta ickekonvexa former, exempelvis flottyrmunkformade supertoroider. En metod som använder GJKalgoritmen skulle behöva bygga upp icke-konvexa former med flera mindre konvexa komponenter. NY-metoden är således bättre för att modellera robotarmar med 6 frihetsgrader. Det är dock i praktiken lättare att implementera GJK-metoden då den endast kräver punktmoln, medan NY kräver parametrar som måste bestämmas eller finjusteras. RST-algoritmen implementerades sist, utformad så att kollisionsdetektionsmetoderna är utbytbara. Det var dock inte möjligt att dra slutsatser utifrån det testdata som erhölls, ty RSTalgoritmens slumpmässiga karaktär. RST-algoritmen kan ses som en multiplikator som endast förstorar de inneboende egenskaperna hos kollisionsdetektionsmetoderna.

One commonly used representation of complex objects in physics-based simulations are triangle meshes. This representation utilizes a collection of triangles to approximate an object. An alternative representation is a Signed Distance Field (SDF). This thesis aims to evaluate the effectiveness of representing a heavy machine bucket as an SDF, specifically in the application of collision detection with a de-formable terrain. Additionally, this thesis describes the implementation of two collision detection routines which uses SDFs to detect collisions with spheres and heightfields. The SDFs are stored using two alternative spatial data structures, a uniform grid and an octree. The implementations are compared against a triangle mesh representation. While there are limitations to the SDF representation, such as the need for high resolutions to capture fine details or that small features may become heavily distorted, the benefits of using SDFs include the ability to perform point to distance queries and provide a robust description of an object’s interior and exterior. The findings of this study showed that the SDF stored in a uniform grid demonstrated better performance in the benchmarks and was able to reproduce comparable data to the triangle mesh in the digging tests. These results indicate that the SDF representation could be a promising alternative to the triangle mesh representation. However, further development and research are required.

In present road traffic system, drone-network based traffic monitoring using the Internet of Vehicles (IoVs) is a promising solution. However, camera-based traffic monitoring does not collect complete data, cover all areas, provide quick medical services, or take vehicle follow-ups in case of an incident. Drone-based system helps to derive important information (such as commuter's behavior, traffic patterns, vehicle follow-ups) and sends this information to centralized or distributed authorities for making traffic diversions or necessary decisions as per laws. The present approaches fail to meet the requirements such as (i) collision free, (ii) drone navigation, and (iii) less computational and communicational overheads. This work has considered the collision-free drone-based movement strategies for road traffic monitoring using Software Defined Networking (SDN). The SDN controllable drone network results in lesser overhead over drones and provide efficient drone-device management. In simulation, two case studies are simulated using JaamSim simulator. Results show that the zones-based strategy covers a large area in few hours and consume 5 kWs to 25 kWs energy for 150 drones (Case study 1). Zone-less based strategies (case study-2) show that the energy consumption lies between 5 kWs to 18 kWs for 150 drones. Further, the use of SDN-based drones controller reduces the overhead over drone-network and increases the area coverage with a minimum of 1.2% and maximum of 2.6%. Simulation (using AnyLogic simulator) shows the 3D view of successful implementation of collision free strategies.