A Comparative Analysis of Numerical Integration in Explicit and Implicit Methods to be Evaluated in the Linkage Model with Multibody Dynamics Toward an Optimum Design of Support Devices for Human Joint Workload Reduction

抄録

In the analysis based on multibody dynamics (MBD), the MBD models are described by ordinary differential equations, and the numerical integration methods applied to the analysis nonnegligibly affect the accuracy of the results. In consideration of models containing dynamic components such as spring dampers and flexible elements, the selection of integration methods is highly important not only for accuracy but also computational costs of the analysis, because it easily causes integration errors. For the development of exoskeleton-type assistive devices using flexible elements, an accurate assessment of the effect of their elastic properties is required. In the present study, we applied the implicit integration method in order to improve the accuracy of MBD-based analysis, and numerical errors in computer experiments were significantly reduced in the case of implicit methods with respect to those caused by explicit methods. This verification result can lead to the improvement of the accuracy of the inverse dynamics analysis based on the flexible multibody dynamics (fMBD) theory.