Abstract

This study proposed a novel robust sliding mode control strategy for the stabilized platform of rotary steering drilling system. Firstly, a Nonlinear Disturbance Observer (NDO) which can converge exponentially with suitable design parameters is used to observe the uncertain disturbance of stabilized platform under work condition. Subsequently, sliding mode controller is designed to guarantee the robustness of the closed-loop system. The adaptive rate of switching gain is designed and sign function is replaced by bipolar sigmoid function to weaken chattering. Finally, Genetic Algorithm (GA) is applied to search the optimal controller parameters, including switching function coefficient, switching gain adaptive coefficient, sigmoid function coefficient and observer coefficient. Simulation results show that NDO can observe the uncertain disturbance effectively, controller output is decreased and stabilized platform can get optimal control performance and robustness.

Keywords:

Genetic algorithm, nonlinear disturbance observer, Stabilized platform, rotary steering drilling system, sliding mode control,

References

Competing interests

The authors have no competing interests.

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Copyright

The authors have no competing interests.