BOND GRAPH MODELING OF MULTIBODY SYSTEMS - A LIBRARY OF 3-DIMENSIONAL JOINTS

The Karnopp-Margolis method of modeling mechanisms is not only intuitively appealing, but it is also equivalent to the classical Lagrangian multiplier approach that produces the dynamic equations in state space form (Zeid, Trans. ASME J. Dyn. Syst. Meas. Control, Vol. 111, pp. 15-23, 1989). This paper details modeling space mechanisms and multibody systems using the Karnopp-Margolis method. A bond graph library is given for six types of joints that are common in building space mechanisms. These joints can be modeled using bond graph processors, or coded using any simulation language macro facility, and then stored in a library of joints. Using a suitable macro capability, bond graph processors, such as ENPORT or CAMP, can easily model multibody systems by using this library of joints. Moreover, bond graph models of joints may be used to investigate nonlinear properties of joints and to develop new types of joints.