Dynamic simulation of the CAD model in SimMechanics with multiple uses

Authors: JIRI ZÁTOPEK, ZDENEK Ú?EDNÍ?EK, JOSÉ MACHADO, JOÃO SOUSA

Abstract: When designing a mechatronic system, several steps are taken into account. One of the main steps is the design of a CAD model representing the physical part of the system, and another major point is the development of the mathematical model necessary for the respective controller design. This paper combines both design steps and shows the advantages of using this approach. First, a CAD model is created considering the kinematic and dynamic behavior of the system as well as respective material properties. This CAD model is, in parallel, used for both purposes: as the main basis for developing a mathematical model that will be used for definition of control laws and appropriate system controllers, and also to generate a physical model as result of exporting to MATLAB/Simulink (Simscape/SimMechanics library) in order to simulate the system behavior. This translation does not consider only the standard CAD model export to the SimMechanics library when forces and torques between links are clearly defined, but also the correct way to add corresponding limiting forces/torques. When comparing the behavior of the physical model and the mathematical model, it is important to obtain similar results, especially when it is necessary to perform some simplifications of a mathematical model, as happens in the context of nonlinear systems control. All these issues are discussed in this paper and the obtained simulation results for both models are similar, which confirms the proposed approach.

Keywords: Model-based design, dynamics, simulation, Simscape, SimMechanics, computer-aided design, motion control

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