Directional Drilling Attitude Control With Input Disturbances and Feedback Delay * *This work was supported by Schlumberger

Output-feedback inclination control of directional drilling systems

Directional drilling techniques, based on rotary steerable systems, are used to generate complex curved boreholes. In practice, however, boreholes drilled with such systems often show instability-induced borehole spiraling, which negatively affects the borehole quality and increases drag losses while drilling. As a basis for controller synthesis, we present a directional drilling model in terms...

On the maximum feedback delay in a linear/nonlinear control system with input disturbances caused by controller-computer failures

Electromagnetic interferences or other environmental disturbances may cause transient failures to the controller computer of a real-time control system. Such a faulty controller either fails to update the control input for one or more sampling periods, or generates erroneous control inputs until the failure is handled properly or disappears. The goal of this paper is to derive the maximum durat...

~- This research was supported by the National Aeronautics and Space

Robust Attitude Control of Spacecraft Simulator with External Disturbances

The spacecraft simulator robust control through H∞-based linear matrix inequality (LMI) and robust adaptive method is  implemented. The spacecraft attitude control subsystem simulator consists of  a  platform, an air-bearing and a set of four reaction wheels. This set up provides a free real-time three degree of freedom rotation. Spacecraft simulators are applied in upgrading and checking the c...

Fractional order robust adaptive intelligent controller design for fractional-order chaotic systems with unknown input delay, uncertainty and external disturbances

In this paper, a fractional-order robust adaptive intelligent controller (FRAIC) is designed for a class of chaotic fractional order systems with uncertainty, external disturbances and unknown time-varying input time delay. The time delay is considered both constant and time varying. Due to changes in the equilibrium point, adaptive control is used to update the system's momentary information a...