PID Based on Sliding Mode Control for Rotary Drilling System

This paper presents a robust controller in order to handle the stick-slip vibrations of a rotary drilling system. Drillstring control is a difficult and complex task. Indeed, there are many difficulties of vibrations during the drilling process. Control design focuses on application of nonlinear control technique, specifically feedback linearization and sliding mode control. Hence, with the objective of attending good performance, sliding mode controller has been introduced. The herein developed controller is, a PID controller based on sliding surface function that works in conjunction with an input state controller to arrive at a controller capable of dealing with a nonlinear system with uncertainties. The sliding mode technique is applied by choosing the bit angular velocity error as the sliding surface. The stabilization and tracking performance of this controller is presented and compared with a classical feedback controller. Numerical simulations have been carried out to verify the idea. The results show faster dynamics and provided the highlight advantages of the controller