Virtual pantograph-catenary environment for control development based on a co-simulation approach

Multibody dynamics methodologies have the potential to integrate in a unique simulation environment the different disciplines, each one with its own equilibrium equations and computational methods. The key issue is not so much the ability to include the different modelling and solution methods in the same computer code, but much more the possibility to handle different codes, eventually programmed with different languages and using their own numerical methods, in a computational environment in which they exchange data in a controlled and efficient form. Such an environment in which different codes co-exist and have coordinated time stepping procedures is defined as a co-simulation. In this work, a co-simulation environment in which a multibody dynamics code is simulated concurrently with a finite element code is presented and demonstrated. The main goal behind this development is to develop a virtual scenario of a realistic interaction between train roof-mounted pantographs and the overhead contact line, also known as catenary, in which different paradigms for the development of mechatronic pantographs can be tested. The multibody code is the simulation tool for the multibody pantograph, while the finite element code is the computational tool in which the catenary is modelled and simulated. Each code has its own time integration algorithm, which require that the equations of motion of both multibody and finite element models are solved at different time instants. This paper proposes a coordination strategy for the time stepping and input-output data required by each of the time integrators that complete the co-simulation environment. The complete co-simulation methodology is demonstrated with the study of the interaction between pantographs and a catenary with the objectives of providing the realistic virtual test ground for the development of mechatronic pantographs and identifying the maximum operation velocity at which the pantograph-catenary couple can operate.