Modeling and Simulation in Engineering

This book provides an open platform to establish and share knowledge developed by scholars, scientists, and engineers from all over the world, about various applications of the modeling and simulation in the design process of products, in various engineering fields. The book consists of 12 chapters arranged in two sections (3D Modeling and Virtual Prototyping), reflecting the multidimensionality of applications related to modeling and simulation. Some of the most recent modeling and simulation techniques, as well as some of the most accurate and sophisticated software in treating complex systems, are applied. All the original contributions in this book are jointed by the basic principle of a successful modeling and simulation process: as complex as necessary, and as simple as possible. The idea is to manipulate the simplifying assumptions in a way that reduces the complexity of the model (in order to make a real-time simulation), but without altering the precision of the results

The 1991 research and technology report, Goddard Space Flight Center

The 1991 Research and Technology Report for Goddard Space Flight Center is presented. Research covered areas such as (1) earth sciences including upper atmosphere, lower atmosphere, oceans, hydrology, and global studies; (2) space sciences including solar studies, planetary studies, Astro-1, gamma ray investigations, and astrophysics; (3) flight projects; (4) engineering including robotics, mechanical engineering, electronics, imaging and optics, thermal and cryogenic studies, and balloons; and (5) ground systems, networks, and communications including data and networks, TDRSS, mission planning and scheduling, and software development and test

An investigation into semi-automated 3D city modelling

Creating three dimensional digital representations of urban areas, also known as 3D city modelling, is essential in many applications, such as urban planning, radio frequency signal propagation, flight simulation and vehicle navigation, which are of increasing importance in modern society urban centres. The main aim of the thesis is the development of a semi-automated, innovative workflow for creating 3D city models using aerial photographs and LiDAR data collected from various airborne sensors. The complexity of this aim necessitates the development of an efficient and reliable way to progress from manually intensive operations to an increased level of automation. The proposed methodology exploits the combination of different datasets, also known as data fusion, to achieve reliable results in different study areas. Data fusion techniques are used to combine linear features, extracted from aerial photographs, with either LiDAR data or any other source available including Very Dense Digital Surface Models (VDDSMs). The research proposes a method which employs a semi automated technique for 3D city modelling by fusing LiDAR if available or VDDSMs with 3D linear features extracted from stereo pairs of photographs. The building detection and the generation of the building footprint is performed with the use of a plane fitting algorithm on the LiDAR or VDDSMs using conditions based on the slope of the roofs and the minimum size of the buildings. The initial building footprint is subsequently generalized using a simplification algorithm that enhances the orthogonality between the individual linear segments within a defined tolerance. The final refinement of the building outline is performed for each linear segment using the filtered stereo matched points with a least squares estimation. The digital reconstruction of the roof shapes is performed by implementing a least squares-plane fitting algorithm on the classified VDDSMs, which is restricted by the building outlines, the minimum size of the planes and the maximum height tolerance between adjacent 3D points. Subsequently neighbouring planes are merged using Boolean operations for generation of solid features. The results indicate very detailed building models. Various roof details such as dormers and chimneys are successfully reconstructed in most cases

Sabertooth: A High Mobility Quadrupedal Robot Platform

Team Sabertooth aimed to design and realize an innovative high mobility, quadrupedal robot capable of delivering a payload over terrain impassable by wheeled vehicles at a speed of 5fps. The robot is designed to ascend and descend stairs. The robot uses a spring system in each of its legs for energy efficient locomotion. The 4\u27x3\u27x3\u27 freestanding four legged robot weighs approximately 300lbs with an additional payload capacity of 30lbs. The passive two degree of freedom body joint allows flexibility in terms of robot motion for going around tight corners and ascending stairs. The system integrates sensors for staircase recognition, obstacle avoidance, and distance calculation. A distributed control and software architecture is used for world mapping, path planning and motion control

Sabertooth: A High Mobility Quadrupedal Robot Platform

Team Sabertooth aimed to design and realize an innovative high mobility, quadrupedal robot platform capable of delivering a payload over terrain otherwise impassable by wheeled vehicles at a speed of 5 feet per second. The robot uses a spring system in each of its legs for energy efficient locomotion. The 4ft x 3ft x 3ft freestanding four legged robot weighs approximately 300 pounds with an additional payload capacity of 30 pounds. An important feature of the robot is the passive, two degree of freedom body joint which allows flexibility in terms of robot motions for going around tight corners and ascending stairs. A distributed control and software architecture is used for world mapping, path planning and motion control

Closing the Performance Gap in Building Energy Modelling through Digital Survey methods and Automated Reconstruction

Against the backdrop of increasing global efforts to mitigate the effects of climate change there has been a large focus on the Built Environment. The low level of building stock turnover in the UK, estimated between 1 3% per annum, has reinforced the importance of robust retrofit programmes to meet legislated targets [1,2]; Experts predict that the majority of existing UK buildings will still be in use in 2050 [3]. Residential and commercial buildings account for approximately 20% of energy end use globally with UK industry building services such as space heating and lighting account for between 6-56% of overall building energy use, depending on sector [4]. Building Energy Modelling and Simulation (BEMS) software is used to assess the energy performance of a building based on knowledge of its construction, design, use and location. While design data is readily available for new buildings, existing buildings, that are in need of retrofit, tend to have limited as-built building data. This requires a collection of data through site surveys and manual creation of building models; This is a time consuming and expensive activity. The aim of this research was “Develop a scientific method to remove barriers to urban scale Building Energy Modelling and Simulation (BEMS) using pattern recognition software to extract built forms from large data sets”. This research has developed a process of rapid geometry generation for BEMS applications to substantially improve this workflow. Following an internal site survey, a Point Cloud was produced of a case-study building. This was automatically processed to create recognisable building geometry for BEMS applications that achieved time savings of 85% over traditional methods. It was identified that internal survey methods present limitations to the automated reconstruction process and that existing offerings for UAV mounted survey equipment required high capital expenditure. A low-cost prototype for external scanning underwent initial development and identified areas for further development. The geometry that was reconstructed via internal survey data was simulated in BEMS and compared against measured energy data. The annual energy use was predicted to within 6% of the measured energy data. Limitations to a full reconstruction led to a hybrid approach being conducted. The hybrid approach predicted annual energy use to within 4% of measured data and met industrial validation requirements. The research conducted has demonstrated that improvements to the BEMS workflow can be achieved and in doing so it can contribute to the reduction in emissions from the Built Environment