7 research outputs found

    T-LESS: An RGB-D Dataset for 6D Pose Estimation of Texture-less Objects

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    We introduce T-LESS, a new public dataset for estimating the 6D pose, i.e. translation and rotation, of texture-less rigid objects. The dataset features thirty industry-relevant objects with no significant texture and no discriminative color or reflectance properties. The objects exhibit symmetries and mutual similarities in shape and/or size. Compared to other datasets, a unique property is that some of the objects are parts of others. The dataset includes training and test images that were captured with three synchronized sensors, specifically a structured-light and a time-of-flight RGB-D sensor and a high-resolution RGB camera. There are approximately 39K training and 10K test images from each sensor. Additionally, two types of 3D models are provided for each object, i.e. a manually created CAD model and a semi-automatically reconstructed one. Training images depict individual objects against a black background. Test images originate from twenty test scenes having varying complexity, which increases from simple scenes with several isolated objects to very challenging ones with multiple instances of several objects and with a high amount of clutter and occlusion. The images were captured from a systematically sampled view sphere around the object/scene, and are annotated with accurate ground truth 6D poses of all modeled objects. Initial evaluation results indicate that the state of the art in 6D object pose estimation has ample room for improvement, especially in difficult cases with significant occlusion. The T-LESS dataset is available online at cmp.felk.cvut.cz/t-less.Comment: WACV 201

    Inkrementální překlad v interaktivních systémech

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    Dissertation thesis deals with possibilities of incremental compiler construction. It represents the compiler construction possibilities for languages with a fixed set of lexical units and for languages with a variable set of lexical units, too. The methodology design for the incremental compiler construction is based on the known algorithms for standard compiler construction and derived for both groups of languages. The part focused on incremental compiling of common programming languages is based on a published methodology of incremental parser construction. The method uses syntax-directed translation scheme. The part focused on incremental compiling of languages with a variable set of lexical units is engaged in incremental compiler construction for on of the typical representantives, typographic system TeX. Unline the frontal compilation it is necessary to adapt the semantic actions to the incremental environment and bring additional information for their links to the appropriate location in the grammar rules. The thesis discusses the problem of the storage of information about current lexical units categories during the repeated compilation and it offers solutions. The thesis also describes the application of proposed methodology in the web application that is used for teaching the course Theory of programming languages at the Faculty of Business and Economics, Mendel University in Brno

    Design of methodology for incremental compiler construction

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    The paper deals with possibilities of the incremental compiler construction. It represents the compiler construction possibilities for languages with a fixed set of lexical units and for languages with a variable set of lexical units, too. The methodology design for the incremental compiler construction is based on the known algorithms for standard compiler construction and derived for both groups of languages. Under the group of languages with a fixed set of lexical units there belong languages, where each lexical unit has its constant meaning, e.g., common programming languages. For this group of languages the paper tries to solve the problem of the incremental semantic analysis, which is based on incremental parsing. In the group of languages with a variable set of lexical units (e.g., professional typographic system TEX), it is possible to change arbitrarily the meaning of each character on the input file at any time during processing. The change takes effect immediately and its validity can be somehow limited or is given by the end of the input. For this group of languages this paper tries to solve the problem case when we use macros temporarily changing the category of arbitrary characters

    Design of a high-specific speed turbine with non-uniform blade cascade

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    This paper presents the hydraulic design of Kaplan type turbine in fully axial configuration. The turbine model consists of a straight pipe intake, a rib which covers the shaft, five axial guide vanes, a six blade runner and a 10,6°-full angle draft tube. Due to the presence of non-uniform velocity field behind the rib and interaction between stator and rotor, the pressure pulsations occur and cause some excitation forces acting on the runner. To reduce these negative phenomena the six non-uniform blade runner has been designed using computational fluid dynamics modelling (CFD). The runner blades are placed in various axial distances from the guide vanes. This new design should reduce the pressure pulsations caused by interaction between the rib and the runner, which is the main negative effect by the current design. The forces and torque which are acting on the runner blades as well as the pressure inside the turbine are observed in time domain. The amplitudes and frequencies are analysed using Fast Fourier Transform (FFT). The frequencies are compared to the modal analysis results of the runner submerged in water. This hydraulic design is based on previous axial turbine, which was designed for small hydro power plant located at Lužnice River. The design point is defined by head H = 1,5 m, volumetric flow rate Q = 2,1 m3/s and RPM n = 260 min-1. This turbine was designed using six runner blades to reduce the pressure, force and torque pulsations caused mainly by wakes, which were observed behind the rib

    Design of a high-specific speed turbine with non-uniform blade cascade

    Get PDF
    This paper presents the hydraulic design of Kaplan type turbine in fully axial configuration. The turbine model consists of a straight pipe intake, a rib which covers the shaft, five axial guide vanes, a six blade runner and a 10,6°-full angle draft tube. Due to the presence of non-uniform velocity field behind the rib and interaction between stator and rotor, the pressure pulsations occur and cause some excitation forces acting on the runner. To reduce these negative phenomena the six non-uniform blade runner has been designed using computational fluid dynamics modelling (CFD). The runner blades are placed in various axial distances from the guide vanes. This new design should reduce the pressure pulsations caused by interaction between the rib and the runner, which is the main negative effect by the current design. The forces and torque which are acting on the runner blades as well as the pressure inside the turbine are observed in time domain. The amplitudes and frequencies are analysed using Fast Fourier Transform (FFT). The frequencies are compared to the modal analysis results of the runner submerged in water. This hydraulic design is based on previous axial turbine, which was designed for small hydro power plant located at Lužnice River. The design point is defined by head H = 1,5 m, volumetric flow rate Q = 2,1 m3/s and RPM n = 260 min-1. This turbine was designed using six runner blades to reduce the pressure, force and torque pulsations caused mainly by wakes, which were observed behind the rib
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