CAUSALITY ISSUES IN ORIENTATION CONTROL OF AN UNDER-ACTUATED DRILL MACHINE

Modelling for Orientation control of a Drill Machine belonging to a class of under actuated system is presented by duly catering for non-causality of the system. A single pair of electromagnetic poles ensure the orientation along x-axis and y-axis of the drill machine. Using the concept of pulse width modulation a controlling signal for the actuators which caters for all practical limitations of the system is generated. The derived discrete time equivalent model overcomes the practical limitation of control techniques used for such class of systems. A novel technique is introduced to avoid system becomes non-casual. A closed form based on discrete time equivalent model supported by simulation results will be helpful in designing overall feedback control for the orientation of the system.