MBS approach to generate equations of motions for HiL-simulations in vehicle dynamics

Numerical simulation of system dynamics is today a standard in the design of cars and trucks. The multibody system (MBS) analysis is applied to suspension kinematics and compliant kinematics, handling performance and ride comfort as well as to the generation of load data for lifetime prediction. These simulation tasks are carried out as an off-line simulation. Over the last couple of years the MBS method has been established in the real-time simulation domain, typically for the design of vehicle control systems and the test of electronic control units, using Hardware-in-the-Loop (HiL) simulation. This paper shows how the transition from offline multi-body-system (MBS) models to real-time simulation can be achieved automatically by using a component oriented reduction procedure for vehicle suspensions, which keeps the full component parameterization. This necessitates a transformation of the equations of motion from differential algebraic equations (DAE) into ordinary differential equations (ODE). For use in HiL-simulators the equations of motion with open interfaces of the applied forces and torques are provided to be integrated in a modular dynamic ride model.