Real-time flexible multibody simulation with Global Modal Parameterization

Many applications require fast and even real-time multibody simulations. Until recently, strongly simplified models were used in order to reach real-time constraints. A novel system-level model reduction technique, namely Global Modal Parameterization (GMP), enables the reduction of a complex mechanism, incorporating flexibility. This technique groups all computationally demanding tasks in a preprocessing phase, which allows the actual simulation to run at real-time. The main strength of the algorithm lies in the fact that the original system of differential-algebraic equations is transformed into a system of ordinary differential equations, which can easily be integrated with explicit methods. This work shortly reviews the GMP-method for systems undergoing 3D motion with multiple rigid DOFs. Furthermore the framework for hard real-time simulation with GMP is discussed. The novelty is the description of a simulation method for a GMP model with an explicit time integrator, which is deployable on hard real-time systems. One of the method’s advantages is the a priori known computational load for each timestep, allowing hard real-time simulations. The method is benchmarked for a flexible spatial slider-crank mechanism, modeled in a commercial flexible multibody package. This is the first application of the GMP-approach on an original floating-frame-of-reference component mode synthesis model undergoing highly dynamical motion.