Stick slip vibration control of drill string based on torque feedforward and sliding mode controller

Abstract

The drill string system in drilling engineering has significant geometric nonlinearity. Due to the frictional torque generated by the interaction between the drill bit and the rock and soil, it is easy to cause the drill string to fall into a sticky sliding vibration state. Based on the two lumped mass torsion pendulum model of the drill string, this paper establishes an observer of the bit speed, and designs a sliding mode controller (TF-SMC) considering the bit torque to suppress the stick slip vibration of the drill string. The simulation results show that compared with PID controller and sliding mode controller, torque feed-forward sliding mode controller can achieve better control effect on drill string at low speed. When torque feedforward sliding mode controller and PID controller are used in parallel, the control effect is better than the first three controllers.