A Simplified Dynamics Block Diagram for a Four-Axis Stabilized Platform

Abstract

It is relatively straight-forward to derive comprehensive dynamics block diagrams for two- and three-axis balanced stabilized platforms. But trying to do it for four and higher order systems is getting rapidly such an amount of work, and the resulting block diagrams so extensive, that sensible simplification from the start if feasible could be very beneficial. Those terms that are going to be insignificantly small relative to the other terms should be left out right from the start when deriving the equations. In this paper a method is shown to simplify the dynamics model of stabilized platforms, with the four-axis platform as the main example. The relevant equations are derived for the four-axis example, the block diagram is compiled from the equations after adding simple control loops around the dynamics model to get to the final expanded block diagram, and then some simulation results are shown. The method is validated by showing that the simulation results for a three-axis system are exactly the same for the comprehensive and simplified block diagrams, using the same method. It is proposed that it is therefore reasonable to expect similar findings for the four-axis case