井下闭环导向钻井工具双环积分滑模控制研究

Research on Dual-loop Integral Sliding Mode Control of Downhole Closed-Loop Steering Drilling Tool

带有双偏心环偏置机构的旋转导向钻井工具在导向钻进时,由于旋转外套传递的钻压以及复杂的井下工况等不确定性及非线性因素,造成钻井工具的轨迹精确度难以控制,为此,提出了一种轨迹跟踪控制理论--双环积分滑模控制。首先,对一种旋转导向钻井工具中的双偏心环偏置机构进行模型简化,将其简化为二自由度的连杆机构;其次,对机构模型进行分析,构建其运动学方程和动力学模型;然后,设计了双环积分滑模控制器,并用Lyapunov函数证明了所设计的控制系统的稳定性;最后,利用MATLAB软件进行仿真分析,证实了该控制方法有较好的抗干扰能力和控制精度。

When rotary steering drilling tools with biasing mechanism of double eccentric rings are used in steering drilling,it is difficult to control the accuracy of the trajectory of the drilling tools because of the uncertainties and non-linear factors such as the drilling pressure transmitted by the rotary jacket and the complex downhole working conditions.Therefore,a trajectory tracking control theory,double-loop integral sliding mode control,is proposed.Firstly,the offset mechanism of double eccentric rings in a rotary steering drilling tool is simplified into a two-degree-of-freedom linkage mechanism.Secondly,the mechanism model is analyzed and its kinematics equation and dynamics model are established.Then,a double-loop integral sliding mode controller is designed,and the stability of the designed control system is proved by Lyapunov function.Finally,it is proved that the control method has good anti-interference ability and control accuracy by means of the simulation analysis using MATLAB software.