Memorias de investigación
Communications at congresses:
On the Gröbner Basis Triangularization of Constraint Equations in Natural Coordinates
Year:2012

Research Areas
  • Engineering

Information
Abstract
Efficient dynamic simulation code is essential in many situations (including hardware-in-the-loop and model-predictive control applications), and highly beneficial in others (such as design optimization, sensitivity analysis, parameter identification, and controller tuning tasks). When the number of modelling coordinates n exceeds the degrees-of-freedom of the system f, as is often the case when closed kinematic chains are present, the governing dynamic equations consist of n second-order ordinary differential equations (ODEs) coupled with m = n ? f algebraic constraint equations. This set of n + m index-3 differential-algebraic equations can be difficult to solve in an efficient yet accurate manner. Embedding (or generalized coordinate partitioning) can be used to obtain f ODEs (one for each independent acceleration), which are generally more amenable to numerical integration; however, the dependent positions are typically computed from the independent positions at each time step. Newton?Raphson iteration is often used for solving the position-level kinematics, but only provides solutions to within a specified tolerance, and can require several iterations to converge. In this work, Gröbner bases are used to obtain recursively solvable symbolic solutions for the dependent positions, which can then be evaluated to within machine precision using a fixed number of arithmetic operations. Natural coordinates are particularly attractive in this context, since the resulting constraint equations are maximally quadratic polynomials and are, therefore, easily triangularized. The proposed approach is suitable for use in an automated formulation procedure and, as demonstrated by two examples, is capable of generating highly efficient simulation code with minimal additional effort required at the formulation stage.
International
Si
Congress
2nd Joint International Conference on Multibody System Dynamics (IMSD)
960
Place
May 29?June 1, 2012, Stuttgart, Germany
Reviewers
Si
ISBN/ISSN
978-3-927618-32-9
Start Date
29/05/2012
End Date
01/06/2012
From page
1
To page
10
Libro de actas
Participants

Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Grupo de Inv. en Seguridad e Impacto Medioambiental de Vehículos y Transportes (GIVET)
  • Centro o Instituto I+D+i: Instituto Universitario de Investigación del Automóvil (INSIA)