A ROV pilot needs to wholly control the behavior of the ROV while it is in execution of object recovery and detection in water. However, most of the commercial ROV operating systems only provide information of video images, depth and orientation. It is difficult for the operator to integrate all information into a vivid picture while steering the vehicle. Besides, limited by the available and expensive operating support, most operators take a lot of practice and field experiences to develop their skill. Therefore, it is necessary to develop a simulator that equips with capabilities of displaying ROV status for real world operation and generating all different operation scenarios for pilot training. This study has developed a multi-function ROV operating virtual environment which integrates all sensory data in real-time to yield a 3D navigation map for operators. Sensory data include GPS, orientation and depth of the ROV, and the acoustic tracking system. In addition to the real physical components connected to the system, a virtual environment for pilot training has constructed. This training environment allows modifying dynamic parameters of the ROV and changing conditions of the ocean environment. Keyboard, joystick and mouse are used as input devices for the system. The developed mathematical model of ROV kinematics and dynamics can generate ROV's corresponding motion according to the commands of the trained-pilot.

Chemnitz, Techn. Univ., Diplomarb., 1997.

No description available.

No description available.

The maneuver of ROV requires considerable pilot skill which is a product of physical and mental practice over a long period of time. However, with the limitations of ROV safety, the availability and high cost of deploying equipment, most of ROV pilots gain the necessary skill through on-the-job training. In this study, we developed a simulation system for ROV pilot training and mission planning. This system is implemented in C++ with the cross-platform OpenGL for 3D graphics. It equips with a scene editor allowing the user to build complex 3D geometric objects from simpler primitives. This editor allows the user to change settings of ambient light intensity, visibility, current speed, and seafloor topography for fulfilling specific training requirements. As well, the user can translate and rotate the entire 3D scene and look at it from different vantage point. Besides, this system provides the user with simple commands for mission planning. For realistically simulating the dynamic behavior of the ROV, the nonlinear hydrodynamic equations of motion of the ROV with six degrees of freedom are applied to describe its motion. Moreover, this system is built with the capability of collision detection for evaluating the collision response of ROV. During the training process, the data engine records all navigation data which can be retrieved and played after conducting a training course. The animation playback function exactly reproduces the scenario that occurs during the period of training. It presents the trainee with the opportunity to review the whole operation scenario. Besides, experiments were designed based on the Taguchi Method to study the effects of different factors on ROV pilot performance. The factors selected for evaluation include ROV trajectory display, underwater visibility, ROV positioning error, and current speed. We found that underwater visibility has the greatest influence on ROV pilot performance, next are ROV positioning error and ROV trajectory display, then the current speed. This result will be helpful in rating the level of difficulty of the training.

Due to the expense and logistics involved with operating real remotely operated vehicles (ROV), training and practice is often difficult to obtain. Therefore, many researches were conducted to increase ROV pilots' experiences through virtual reality. However, most of the training systems that are in use today can only be controlled by a single operator. When two or more ROVs work in a same area, it needs proper concordance among pilots in order to avoid accidents such as collision or cable entanglement. Therefore, this study aims at the development of a ROV operating interface featuring simulated training, remote monitoring, and multiple-user connections. For fulfilling the requirements of remote monitoring, simulated training and multiple-user connections, this study employs JAVA and GL4Java in developing the ROV operating interface. This way we benefit from the 3D description capabilities of GL4Java while JAVA is utilized for the processing and manipulation of web interactions. The developed system architecture includes a server and a client. The client can connect to server by using the web browser through the internet or a LAN with TCP/IP. The server contains required data of sea floor topography and ROV dynamics related parameters. As well, the server is responsible for communicating with the clients. On the client site, it is responsible for sending commands, receiving sensor data and keeping the local information up to date. In remote monitoring, the server periodically integrates and records ROV positioning data and then transmits them to the client. The client receives the updates of ROV status information and displays them on the graphical interface. In simulated training, the equations of motion of ROV are computed on the client-side and only simulated positioning data is reported to the server. In addition, the system allows users to modify underwater visibility, intensity of ambient light and terrain texture for simulating diverse operation conditions.

Stuttgart, Univ., Diplomarb., 2002.

Level of detail algorithms have widely been implemented in architectural VR walkthroughs and video games, but have not had widespread use in VR terrain visualization systems. This thesis explains a set of optimizations to allow most current level of detail algorithms run in the types of multiple display systems used in VR. It improves both the visual quality of the system through use of graphics hardware acceleration, and improves the framerate and running time through modifications to the computations that drive the algorithms. Using ROAM as a testbed, results show improvements between 10% and 100% on varying machines.

A complexidade dos sistemas de visualização imersivos pode variar tremendamente conforme a sua aplicação. Algumas ferramentas mais simples fazem uso de um único óculos de Realidade Virtual como infraestrutura de visualização. No entanto, aplicações mais complexas, como simuladores e outras ferramentas de treinamento, podem necessitar de uma infraestrutura distribuída, contendo diversos computadores e telas. Alguns simuladores e outras aplicações de treinamento fazem uso frequente de periféricos sofisticados de interação, que reproduzem de maneira fiel os elementos encontrados no cenário real. Além disto, o espaço de treinamento pode ser compartilhado por dois ou mais usuários. Estes requisitos acabam por impor o uso de sistemas de visualização complexos e distribuídos, que visam cobrir de maneira quase completa o campo de vis~ao destes usuários. Por causa das características deste tipo de sistema, as aplicações desenvolvidas nestes cenários são inerentemente complexas, pois frequentemente consideram aspectos específicos da infraestrutura para realizar a distribuição e o sincronismo da cena virtual. Esta complexidade dificulta o desenvolvimento, a manutenção e a interoperabilidade destas ferramentas. Este trabalho apresenta uma arquitetura de comunicação para promover o uso de sistemas imersivos de forma simples e transparente para as aplicações, viabilizando o uso de infraestruturas complexas e distribuídas. A arquitetura proposta utiliza o mecanismo de substituição do driver OpenGL para obter, de forma automática, a distribuição do aspecto gráfico das aplicações. Apesar deste conceito já ter sido discutido na literatura, esta proposta apresenta um conjunto de técnicas para contornar as limitações inerentes desta abordagem e obter ganhos de desempenho significativos, com resultados consistentes em um amplo conjunto de infraestruturas. As técnicas apresentadas neste trabalho sugerem, entre outras coisas, o uso de recursos modernos do padrão OpenGL para reduzir o volume de comunicação entre CPU e GPU. Um dos recursos avaliados foi o uso de mecanismos de renderização indireta, onde a aplicação armazena os comandos de renderização na memória da placa gráfica. Juntamente com esta técnica, o trabalho também investigou o uso de um algoritmo de culling na própria GPU, o que permitiu que esta otimização fosse utilizada mesmo em sistemas com arranjos mais complexos de tela. Os resultados obtidos mostram que a aplicação pode exibir o seu conteúdo em um conjunto amplo de sistemas imersivos, contendo mais resolução e mais geometria visível, sem deteriorar o seu desempenho. Os testes foram conduzidos em diferentes infraestruturas e com cenas de tamanhos variáveis. Nos casos mais complexos, as técnicas propostas podem reduzir em 86% o tempo médio de renderização, quando comparadas com as abordagens tradicionais. / The complexity of immersive visualization systems can vary tremendously depending on their application. Some simple tools might only require a conventional virtual reality goggle as a visualization infrastructure. However, more complex applications, such as simulators and other training tools, might require a distributed infrastructure, containing several computers and screens. Some training applications and simulators invariably make use of physical peripherals for interaction, which are designed to faithfully reproduce the elements found in real scenarios. Furthermore, the training area may be shared by two or more users. These requirements usually impose the use of complex and distributed imaging systems, which are intended to cover almost the entire field of view of the users involved. Because of the characteristics of this type of system, the applications developed for these infrastructures are inherently complex. They are required to consider specific aspects of the infrastructure itself to carry out the distribution and synchronization of the virtual scene. This complexity hampers the development, maintenance and interoperability of these tools. This work presents a communication architecture to promote the use of immersive systems by allowing applications to use complex and distributed infrastructures in a simple and transparent way. The proposed architecture uses the approach of replacing the OpenGL driver to transparently achieve graphics distribution. Although this has already been discussed in the literature, this document presents a set of techniques to overcome the inherent limitations of this approach and ultimately achieve significant performance gains, with consistent results across a broad range of infrastructures. The techniques presented here suggest, among other things, the use of modern features of the OpenGL standard to reduce the communication overhead between CPU and GPU. One of the features evaluated was the usage of indirect rendering, where the application stores all the rendering commands in the graphics card dedicated memory. Along with this feature, the work also investigated the use of a culling algorithm on the GPU itself, which allowed this optimization to be used even on systems containing screens with a more complex layout. The results show that the application can render its content in a wide range of immersive systems, with higher resolution and more visible geometry, without degrading its performance. The tests were conducted at different infrastructures and scenes with variable sizes. In the more complex use cases, the proposed techniques can reduce by up to 86% the average rendering time, when compared to the traditional approaches.

A complexidade dos sistemas de visualização imersivos pode variar tremendamente conforme a sua aplicação. Algumas ferramentas mais simples fazem uso de um único óculos de Realidade Virtual como infraestrutura de visualização. No entanto, aplicações mais complexas, como simuladores e outras ferramentas de treinamento, podem necessitar de uma infraestrutura distribuída, contendo diversos computadores e telas. Alguns simuladores e outras aplicações de treinamento fazem uso frequente de periféricos sofisticados de interação, que reproduzem de maneira fiel os elementos encontrados no cenário real. Além disto, o espaço de treinamento pode ser compartilhado por dois ou mais usuários. Estes requisitos acabam por impor o uso de sistemas de visualização complexos e distribuídos, que visam cobrir de maneira quase completa o campo de vis~ao destes usuários. Por causa das características deste tipo de sistema, as aplicações desenvolvidas nestes cenários são inerentemente complexas, pois frequentemente consideram aspectos específicos da infraestrutura para realizar a distribuição e o sincronismo da cena virtual. Esta complexidade dificulta o desenvolvimento, a manutenção e a interoperabilidade destas ferramentas. Este trabalho apresenta uma arquitetura de comunicação para promover o uso de sistemas imersivos de forma simples e transparente para as aplicações, viabilizando o uso de infraestruturas complexas e distribuídas. A arquitetura proposta utiliza o mecanismo de substituição do driver OpenGL para obter, de forma automática, a distribuição do aspecto gráfico das aplicações. Apesar deste conceito já ter sido discutido na literatura, esta proposta apresenta um conjunto de técnicas para contornar as limitações inerentes desta abordagem e obter ganhos de desempenho significativos, com resultados consistentes em um amplo conjunto de infraestruturas. As técnicas apresentadas neste trabalho sugerem, entre outras coisas, o uso de recursos modernos do padrão OpenGL para reduzir o volume de comunicação entre CPU e GPU. Um dos recursos avaliados foi o uso de mecanismos de renderização indireta, onde a aplicação armazena os comandos de renderização na memória da placa gráfica. Juntamente com esta técnica, o trabalho também investigou o uso de um algoritmo de culling na própria GPU, o que permitiu que esta otimização fosse utilizada mesmo em sistemas com arranjos mais complexos de tela. Os resultados obtidos mostram que a aplicação pode exibir o seu conteúdo em um conjunto amplo de sistemas imersivos, contendo mais resolução e mais geometria visível, sem deteriorar o seu desempenho. Os testes foram conduzidos em diferentes infraestruturas e com cenas de tamanhos variáveis. Nos casos mais complexos, as técnicas propostas podem reduzir em 86% o tempo médio de renderização, quando comparadas com as abordagens tradicionais. / The complexity of immersive visualization systems can vary tremendously depending on their application. Some simple tools might only require a conventional virtual reality goggle as a visualization infrastructure. However, more complex applications, such as simulators and other training tools, might require a distributed infrastructure, containing several computers and screens. Some training applications and simulators invariably make use of physical peripherals for interaction, which are designed to faithfully reproduce the elements found in real scenarios. Furthermore, the training area may be shared by two or more users. These requirements usually impose the use of complex and distributed imaging systems, which are intended to cover almost the entire field of view of the users involved. Because of the characteristics of this type of system, the applications developed for these infrastructures are inherently complex. They are required to consider specific aspects of the infrastructure itself to carry out the distribution and synchronization of the virtual scene. This complexity hampers the development, maintenance and interoperability of these tools. This work presents a communication architecture to promote the use of immersive systems by allowing applications to use complex and distributed infrastructures in a simple and transparent way. The proposed architecture uses the approach of replacing the OpenGL driver to transparently achieve graphics distribution. Although this has already been discussed in the literature, this document presents a set of techniques to overcome the inherent limitations of this approach and ultimately achieve significant performance gains, with consistent results across a broad range of infrastructures. The techniques presented here suggest, among other things, the use of modern features of the OpenGL standard to reduce the communication overhead between CPU and GPU. One of the features evaluated was the usage of indirect rendering, where the application stores all the rendering commands in the graphics card dedicated memory. Along with this feature, the work also investigated the use of a culling algorithm on the GPU itself, which allowed this optimization to be used even on systems containing screens with a more complex layout. The results show that the application can render its content in a wide range of immersive systems, with higher resolution and more visible geometry, without degrading its performance. The tests were conducted at different infrastructures and scenes with variable sizes. In the more complex use cases, the proposed techniques can reduce by up to 86% the average rendering time, when compared to the traditional approaches.