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Robot Path and Motion Planning
Published in Jitendra R. Raol, Ajith K. Gopal, Mobile Intelligent Autonomous Systems, 2016
In the visibility map/graph (VMG) the vertices are connected if (and only if) there is an unobstructed line of sight (LOS) between them [1]. The cost is given as the actual distance between the vertices. In a simple visibility map the vertices of the graph are placed on the corners of the obstacles as well as on the starting and goal positions, and it is referred to as a visibility graph. Here, the assumption is that the obstacles in the environment are polygons (or they can be contained within polygons). To obtain the VMG the visibility between every pair of vertices in the graph must be determined. Each vertex is taken and the visibility between that vertex and every other vertex is calculated; this is done using a rotational plane sweep algorithm thereby reducing the number of polygon edges to consider when testing the visibility between two vertices.
2D GIS
Published in Christopher M. Gold, Spatial Context: An Introduction to Fundamental Computer Algorithms for Spatial Analysis, 2018
Firstly topological network errors where line segments fail to meet, or intersect, do not cause topological errors in the underlying map: graph queries of the type discussed above may be used to detect small gaps or very short intersecting segments. There is no need to rebuild the whole network to fix errors, as is the case with traditional one-dimensional arcs: a navigable map is always available and local searches within it are always valid. Thus minor connectivity errors of the map objects – the roads – may be fixed locally, and often automatically.
Legends of the dashboard: an empirical evaluation of split and joint layout designs for geovisual analytics interfaces
Published in International Journal of Digital Earth, 2023
Izabela Gołębiowska, Tomasz Opach, Arzu Çöltekin, Jolanta Korycka-Skorupa, Jan Ketil Rød
We divided both multiple- and single-legend layouts into Areas of Interest (AOI) representing Views (the three panels where the data are presented: map, graph, and table), and Legends (display elements where symbology and interactive functions were explained). In the multiple-legend layout, AOI Legend was fragmented and scattered across the display (green-turquoise areas in Figure 5 left) compared to the single-legend layout (Figure 5 right). However, in both layouts, the total area of Legends and Views had similar shares in the screen space. AOI Views consisted of three views (a map, a graph, and a table) and a status box that covered 68.0% of the interface area in the multiple-legend layout and 69.3% in the single-legend layout. AOI Legend consisted of an attribute selection control panel (the type of hazard, the type of insurance data, and the year), a map key and a county list. AOI Legend is covered in the multiple-legend layout, 30.5% of the interface space, and 29.1%, in the single-legend layout.
Effectiveness of synthetic coolant at 0°C on machining of SS304 with PVD coated TiCN tool to evaluate and compare tool wear and surface finish with conventional machining method
Published in Tribology - Materials, Surfaces & Interfaces, 2023
The heat generation and temperature rise during machining has a direct impact on tool life [29]. It has been found from various past works that a small temperature rise reduces tool life as there is the plastic deformation of the edge of the cutting tool and also due to thermal stresses there is cracking of the tool flank leading to premature failure [30]. The heat map graph for machining with different parameters is shown in Figure 4. The heat map graph indicates that with a rise in cutting velocity, the temperature at the work tool zone also increases. The temperature rise is controlled at high speed if TiCN coated tool is used with synthetic coolant at 0°C. The results obtained indicate that TiCN coating reduces the heat generation as the coating has low co-efficient of friction resulting in less frictional resistance between tool and workpiece and considerable low heat generation than conventional machining done with tungsten carbide inserts [31]. The best results are obtained when the TiCN-coated tool is used in combination with 0°C synthetic coolant as heat dissipation takes place at a more rapid rate due to the low temperature of coolant splashed over the workpiece area.
High-definition map update framework for intelligent autonomous transfer vehicles
Published in Journal of Experimental & Theoretical Artificial Intelligence, 2021
Muhammed Oguz Tas, Hasan Serhan Yavuz, Ahmet Yazici
SLAM: 2D grid-based mapping is sufficient for the localisation of the robot basically and it can also be considered as a fundamental stage to form the HD map. In this study, we use an RGB-D camera and RTAB mapping to handle visual SLAM. RTAB-Map is realised using the ROS (ROS, 2018) software package. The algorithm produces a map graph which is incrementally created and optimised when a loop closure is detected. The output of the algorithm is the most recent local graph added to the map. It uses the RGB image, the depth information, and laser scan data to obtain the map. As the algorithm reaches its final stage, it defines the optimised state of the graph. Overall location information is kept in a ‘position sequence’ and the sequential positions are linked together. Although the position information for visual objects are available in this map, the identity of these objects and the relation of them with the HD map is unknown. The following object detection and localisation framework can be used to define the identities of the objects.