@ARTICLE{Portal_Ricardo_José_Fontes_Contact_2010,
 author={Portal, Ricardo José Fontes and Dias, João Manuel Pereira and de Sousa, Luís Alberto Gonçalves},
 volume={vol. 57},
 number={No 2},
 journal={Archive of Mechanical Engineering},
 pages={165-186},
 howpublished={online},
 year={2010},
 publisher={Polish Academy of Sciences, Committee on Machine Building},
 abstract={This paper presents a methodology for contact detection between convex quadric surfaces using its implicit equations. With some small modifications in the equations, one can model superellipsoids, superhyperboloids of one or two sheets and supertoroids. This methodology is to be implemented on a multibody dynamics code, in order to simulate the interpenetration between mechanical systems, particularly, the simulation of collisions with motor vehicles and other road users, such as cars, motorcycles and pedestrians. The contact detection of two bodies is formulated as a convex nonlinear constrained optimization problem that is solved using two methods, an Interior Point method (IP) and a Sequential Quadratic Programming method (SQP), coded in MATLAB and FORTRAN environment, respectively. The objective function to be minimized is the distance between both surfaces. The design constraints are the implicit superquadrics surfaces equations and operations between its normal vectors and the distance itself. The contact points or the points that minimize the distance between the surfaces are the design variables. Computational efficiency can be improved by using Bounding Volumes in contact detection pre-steps. First one approximate the geometry using spheres, and then Oriented Bounding Boxes (OBB). Results show that the optimization technique suits for the accurate contact detection between objects modelled by implicit superquadric equations.},
 type={Artykuły / Articles},
 title={Contact detection between convex superquadric surfaces},
 URL={http://ochroma.man.poznan.pl/Content/104292/PDF/04_paper.pdf},
 doi={10.2478/v10180-010-0009-8},
 keywords={contact detection, superquadrics, optimization, multibody dynamics},
}