Three-dimensional dubins path generation and following for a UAS glider

2017 ◽  
Author(s):  
Pedro F. A. Di Donato ◽  
Ella M. Atkins
Keyword(s):  
Three Dimensional ◽  
Path Generation ◽  
Dubins Path

Tool Path Optimization of 2D Contour Considering Stock Boundary

2012 ◽  
Vol 251 ◽  
pp. 169-172
Author(s):  
Fu Zhong Wu
Keyword(s):  
Present Method ◽  
Tool Path ◽  
Three Dimensional ◽  
Boundary Curve ◽  
Tool Path Generation ◽  
Path Optimization ◽  
Path Generation ◽  
Offset Curves ◽  
Measuring Machine ◽  
Tool Diameter

Based on analyzing the existing algorithms, a novel tool path generation of 2D contour considering stock boundary is presented. Firstly the boundary points of stock are obtained by three-dimensional measuring machine. And the boundary curve is constructed by method of features identifying. The stock boundary is offset toward outside with tool diameter. An enclosed region is formed between the contour curves and the offset curves of stock boundary. The tool path is generated by form of parallel spiral by offsetting the stock boundary in the enclosed region. Finally the validity of present method is demonstrated by an example.

Run-Time Three-Dimensional Blend-Path Generation for Cobot Constraint Surfaces

2002 ◽  
Author(s):  
Eric L. Faulring ◽  
J. Edward Colgate
Keyword(s):  
Three Dimensional ◽  
Path Generation ◽  
One Dimensional ◽  
Mode Operation ◽  
Initial Location ◽  
Free Mode ◽  
Run Time ◽  
Continuous Curvature ◽  
Constraint Surface ◽  
Typical Scenario

During human-cobot interaction, transitions often occur between free mode operation and constraint surface following. This paper considers the following typical scenario: an operator of a three-dimensional (e.g. x-y-z or x-y-θ) cobot commands a “join” from free mode to a one-dimensional constraint path. To ensure that this transition is smooth and responsive, a “blend path” is computed that joins the cobot’s initial location to a location on the constraint path. The blend path must match tangency and curvature at each end, and must also exhibit continuous curvature. A novel “triple-clothoid” algorithm is developed that meets these requirements. In addition, we demonstrate that the triple-clothoid is particularly amenable to x-y-θ systems via implementation on a planar cobot.

An Octree Approach to Rough Machining

1987 ◽  
Vol 201 (3) ◽  
pp. 157-163 ◽  
Author(s):  
M F Yuen ◽  
S T Tan ◽  
W S Sze ◽  
W Y Wong
Keyword(s):  
Three Dimensional ◽  
Numerical Control ◽  
Path Generation ◽  
Layer By Layer ◽  
Rough Machining ◽  
Numerical Control Machining ◽  
Solid Models ◽  
Cutter Path ◽  
Jigs And Fixtures ◽  
Cutter Path Generation

This paper presents an octree subdivision based algorithm of automatic cutter path generation for machining on a numerical control machining centre. Both the stock and the part are represented by solid models. The machining strategy is based on a layer by layer approach taking care of the cutter strength and the variation of the part geometry. This approach allows the problem to be reduced from a three-dimensional to a two-dimensional cutter path generation problem which is solved by a quadtree representation of the plane. The method can be easily extended to include the jigs and fixtures and any other obstacles which would be represented by solid models. Algorithms are described in Pascal-like structure.

scholarly journals Dubins path generation for a fixed wing UAV

2014 ◽  
Author(s):  
Israel Lugo-Cardenas ◽  
Gerardo Flores ◽  
Sergio Salazar ◽  
Rogelio Lozano
Keyword(s):  
Path Generation ◽  
Dubins Path

scholarly journals LIM kinases are required for invasive path generation by tumor and tumor-associated stromal cells

2010 ◽  
Vol 191 (1) ◽  
pp. 169-185 ◽  
Author(s):  
Rebecca W. Scott ◽  
Steven Hooper ◽  
Diane Crighton ◽  
Ang Li ◽  
Ireen König ◽  
...  
Keyword(s):  
Stromal Cells ◽  
Matrix Protein ◽  
Serum Response Factor ◽  
Three Dimensional ◽  
Squamous Carcinoma ◽  
Path Generation ◽  
Matrix Remodeling ◽  
Squamous Carcinoma Cells ◽  
Collagen Contraction ◽  
Collective Invasion

LIM kinases 1 and 2 (LIMK1/2) are centrally positioned regulators of actin cytoskeleton dynamics. Using siRNA-mediated knockdown or a novel small molecule inhibitor, we show LIMK is required for path generation by leading tumor cells and nontumor stromal cells during collective tumor cell invasion. LIMK inhibition lowers cofilin phosphorylation, F-actin levels, serum response factor transcriptional activity and collagen contraction, and reduces invasion in three-dimensional invasion assays. Although motility was unaffected, LIMK inhibition impairs matrix protein degradation and invadopodia formation associated with significantly faster recovery times in FRAP assays indicative of reduced F-actin stability. When LIMK is knocked down in MDA-MB-231 cells, they lose the ability to lead strands of collectively invading cells. Similarly, when LIMK activity is blocked in cancer-associated fibroblasts, they are unable to lead the collective invasion of squamous carcinoma cells in an organotypic skin model. These results show that LIMK is required for matrix remodeling activities for path generation by leading cells in collective invasion.

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