Control Method to Suppress Stick-slip in Drill-strings Featuring Actuation Delay and Constraints

In this work, performance of a modified-integral resonant controller with integral tracking is investigated numerically under the effects of actuator delay and actuation constraints. Actuation delay and constraints naturally limit controller performance, so much so that it can cause instabilities. A 2-DOF drill-string with a nonlinear bit-rock interaction model is analysed. The aforementioned control scheme is implemented on this system and analysed under the effects of actuation delay and constraints and it is found to be highly effective at coping with these limitations. Lastly, the scheme is analysed in detail by varying its gains as well as varying system parameters, most notably that of actuation delay.