  This paper applies the multibond graph approach for rigid multibody systems
to model the dynamics of general spatial mechanisms. The commonly used quick
return mechanism which comprises of revolute as well as prismatic joints has
been chosen as a representative example to demonstrate the application of this
technique and its resulting advantages. In this work, the links of the quick
return mechanism are modeled as rigid bodies. The rigid links are then coupled
at the joints based on the nature of constraint. This alternative method of
formulation of system dynamics, using Bond Graphs, offers a rich set of
features that include pictorial representation of the dynamics of translation
and rotation for each link of the mechanism in the inertial frame,
representation and handling of constraints at the joints, depiction of
causality, obtaining dynamic reaction forces and moments at various locations
in the mechanism and so on. Yet another advantage of this approach is that the
coding for simulation can be carried out directly from the Bond Graph in an
algorithmic manner, without deriving system equations. In this work, the
program code for simulation is written in MATLAB. The vector and tensor
operations are conveniently represented in MATLAB, resulting in a compact and
optimized code. The simulation results are plotted and discussed in detail.
