An Object Oriented Modeling Approach to Intelligent Variable Geometry Trusses

Abstract

Since an intelligent variable geometry truss (IVGT) is usually equipped with large numbers of redundant actuators for the sake of providing adaptivity, a distributed control is considered a promising approach to dealing with its motion control. In this case, a modeling approach and an integrated model is a key to constructing distributed control systems from both hardware and software. To this end, this paper proposes an object-oriented modeling approach. Through decomposing the control problem domain underlying VGTs into objects, an object model can be obtained to represent various object abstractions and the relationships among these objects. It is shown in this paper that an object model of VGTs is exactly the integrated model for their knowledge organizations as well as the control architectures. Two control schemes resulting from the object models-a hierarchical distributed control and an autonomous distributed control-are discussed in particular. To verify the concepts addressed in this paper, an experimental prototype of IVGTs was manufactured, with a two-level hierarchical distributed control system equipped. With this prototype, an experiment is carried out, simulating a self-construction of space structures with IVGTs in a null gravity space.

Performance of an Active Composite Strut for an Intelligent Composite Modified Stewart Platform for Thrust Vector Control

“…Active control systems are effective in controlling the vibrations of structural elements such as rods, columns, beams, plates, and shells. Active struts with vibration suppression capabilities have been studied by Boyd et al (2001), Quenon et al (2001), Fujita et al (1998), Song et al (1999), Dekens and Neat (1999), O'Brien et al (1998), Hyde and Davis (1998), Masters and Crawley (1997), Huang et al (1997), Darby and Pellegrino (1997), and Wada et al (1990). Active struts have primarily been used for vibration suppression to maintain precision positioning rather than a direct precision positioning function.…”

Finite Element Method for Active Vibration Suppression of Smart Composite Structures using Piezoelectric Materials

“…In this case, the piezo is a thick small flat patch PZT-5H with n ¼ 1. Using analytical Equation ( 6) one can obtain Equation (11). This same model was generated in ANSYS FEA and a voltage of U Â n ¼ (100) (1) V was applied to the model.…”

“…As previous work in terms of active struts, researchers developed active struts with vibration suppression capabilities [3][4][5][6][7][8][9][10][11][12][13]. Active struts have primarily been used for vibration suppression to maintain precision positioning rather than a direct precision positioning function.…”