Go to content

Oliver Braun - Multibody Simulation using sympy, scipy and vpython

Oliver Braun - Multibody Simulation using sympy, scipy and vpython [EuroPython 2015] [20 July 2015] [Bilbao, Euskadi, Spain] The talk is about the implementation of multibody simulation in the scientific python world on the way to a stage usefull for engineering and educational purposes. Multibody simulation (MBS) requires two major steps: first the formulation of the specific mechanical problem. Second step is the integration of the resulting equations. For the first step we use the package sympy which is on a very advanced level to perform symbolic calculation and which supports already Lagrange's and Kane's formalism. The extensions we made are such that a complex mechanical setup can be formulated easily with several lines of python code. The functionality is analogous to well known MBS-tools, with that you can assemble bodies, joints, forces and constraints. Also external forces even in a cosimulation model can be added on top. The second step, the integration is done via ode- integrators implemented in scipy. Finally for visual validation the results are visualized with the vpython package and for further analytics with matplotlib. Conclusion: not only highly constrained pendulums with many rods and springs but also driving simulation of passenger cars an be performed with our new extension using python packages off the shelf.

July 20, 2015