A REAL-TIME HARDWARE-IN-THE-LOOP SIMULATOR FOR ROBOTICS APPLICATIONS

Abstract

This paper presents an application to robotics modeling of the multibody free soft- ware MBDyn in its real-time variant. Real-time simulation of robots is usually carried on using dedicated software because of the stringent requirements in terms of solution time for each time step. The real-time variant of the general-purpose multibody simulation software MBDyn orig- inated from the need to share a common simulation environment for the detailed and the real- time analysis of complex, heterogeneous multidisciplinary mechanisms, like robots, helicopter and tiltrotor wind-tunnel models, aircraft landing gear and hydro-mechanical components, and more. The capability to simulate the same problem with increasingly detailed models, ranging from compact models for real-time applications to highly sophisticated models for fully detailed analysis and verification, sharing the same model layout and common parts where limited detail suffices, represents a great advantage because the analyst can work in a single, dependable environment. This paper illustrates recent advances in the real-time performances of the simulation frame- work based on MBDyn for space robotics control applications; focus is on performances im- provement when addressing and very small (in a sparse matrix sense) problems, and on realistic joint friction models.