Adaptive control of drilling by identifying parameters of object model under nonstationarity conditions

Abstract

Purpose. The research is intended to investigate and synthesize adaptive control over drilling by identifying parameters of an object model under non-stationarity conditions. Methods. Under conditions of rapidly changing borehole drilling indices, a two-level adaptive control strategy is applied, combining investigation of drilling and its control. The structure of the control system includes an additional block of forming the model on the basis of data on indirect features. Findings. The research develops a method for seeking the extremum developed for the object whose dynamics is described by a first-order linear differential equation. The method allows to determine the value of the output signal by evaluating the initial phase of the transient process caused by the changed input signal for a set step. Originality. The suggested algorithm of noise-free identification makes it possible to assess the factor of the control object transfer under the action of random disturbances. The data obtained is used to adjust the gain factor of the controller in the closed loop automatic control system of drilling. Practical implications. The suggested structure and algorithm of drilling control allow enhancing drilling efficiency by ensuring relevant mechanical drilling rates through defining corresponding rotation speeds and axial loads of a drilling tool.