Co-simulation correction in multibody systems through eigenstructure assignment

In co-simulation setups, the overall system dynamics is split into several subsystems that evolve in time separately. The exchange of information between subsystems to provide the inputs for the simulation of the others is handled through an interface that manages the co-simulation performing the numerical extrapolation of the data. In this light, the limited exchange of data can cause accuracy and stability issues in the simulation. This work provides an analysis of this critical problem, revealing that coupling subsystems through a co-simulation interface introduces a time-delay in the exchange of data that perturbates the system eigenstructure and hence the accuracy and the stability of the co-simulated system. Hence, a correction algorithm exploiting the paradigm of eigenstructure assignment is proposed to compensate for such perturbations of both the system poles and of the eigenvectors. The effectiveness of the proposed method is assessed through its application to the explicit co-simulation of a benchmark multibody system.