Nonlinear dynamics model of servo platform for steering drilling tool

Abstract

The funct i on of the servo p latform i s to control the borehole's deviat i on and or i entation by us i ng an automatic control method to dr i ve the platform sus p end i ng at a special angle. However, i t i s not an easy job to control th i s cylindr i cal and rotat i ng platform at a part i cular angle under the complex downhole env i ronment. The key to solve th i s p roblem is to establish a su i table nonl i near model. Based on the structure analysis of the p latform, a general law of dynam i cs equation is obtained by analyzing friction, dr i ll i ng fluid shock, eccentric action, etc. A hydraulic driving torque test has been done, wh i ch i nd i cates that the dynam i cs analys i s i s reasonable. The model l i es the foundat i on for the research of p latform's control method and the improvement of mechan i cal des i gn.

Backstepping sliding mode control of stabilized platform for fully rotary steerable drilling system based on nonlinear disturbance observer

“…The PWM generator can be simply regarded as an amplification section and described as $$${u}_{3}(t)={K}_{s}{u}_{2}(t),$$$where K s = 1 is the amplification gain 11 . Thus, Equation () becomes $$${u}_{3}(t)={u}_{2}(t).$$$…”

“…The stability of the stabilized platform system is correlated with the assigned toolface angle. In practice, the assigned toolface angle is stable within certain ranges with the same control method and same parameters and potentially becomes unstable in other ranges 11 . Simulations are conducted with setpoints of 0.5π, 0.6π, and π to demonstrate the adaptability of the proposed control method.…”

“…Tang et al 10 designed the cascaded controller for the stabilized platform and conducted an extended experimental study on platform control algorithms and control parameters, which achieved short‐term stability of the platform system under specific conditions. Wang 11 established a nonlinear dynamic model for the stabilized platform, laying the foundation for theoretical research in control methods. Wang et al 12 formulated the nonlinear dynamic equation governing the stabilized platform.…”

Attitude Control of Stabilized Platform Based on Deep Deterministic Policy Gradient with Disturbance Observer

“…In comparison to traditional control methodologies, DDPG stands out for its adaptability and robustness [13]. Furthermore, DDPG demonstrates excellent generalization capabilities and scalability, rendering it suitable for a wide array of control scenarios and system dynamic models [14,15]. Therefore, in this study, the DDPG algorithm is applied to the control system of a rotary steering drilling stabilized platform; building upon this foundation, we introduce a novel approach, the Disturbance-Observer-Based Deep Deterministic Policy Gradient, to effectively counteract the impact of non-linear frictional disturbances.…”