Structural Optimization of Components in Controlled Mechanical Systems

Abstract

The importance of computer aided engineering in product development processes and research has been increasing rapidly throughout the past years. Today’s software can e.g. help to optimize complex components regarding different objectives or conditions. The capability of these tools has been proved in many industrial applications. They are used in order to improve the products on the one hand and to reduce the development time, and therefore, the costs of the product development on the other hand. New studies in the field of structural optimization concentrate on dynamically loaded parts in mechanical systems. In the state-of-the-art process and methods it is assumed that there exists a set of external loads or load functions acting on the part. The fact that due to geometric modifications caused by an optimization process, changes of the system’s dynamic properties and its overall behaviour may be neglected. In order to take into account the interaction between part and system with all its consequences for the optimization process, a simulation of the complete system is integrated into the optimization process within the research work presented in this paper. Dynamic systems today very often are controlled. The control has a major influence on the dynamic characteristics of the system. Therefore the target is to take into account the aspects of the control system as well during a topology optimization process of the mechanical part in a mechatronic system. Here, a hybrid multibody system simulation, that is, a MBS containing flexible bodies, in conjunction with a Co-Simulation of the control system is integrated into the optimization process. A humanoid robot is an example for such a complex mechatronic system. The goal of the collaborative research centre 588 “learning and cooperating multimodal robots” at the University of Karlsruhe (TH) is the development of robots that can help the human fulfilling everyday tasks in a human environment. The research work presented in this paper is a contribution towards the integration of existing isolated methods into a continuous process. The benefits will be illustrated by an example. The focus is set on the design of the mechanical parts in conjunction with an automatic parameter adaption (optimization) of the control system. Finite element analysis, multibody simulation, control design tools, parameter optimization and topology optimization are tied together into one process to allow an efficient optimization of structures “within” their surrounding mechatronic system.