Adaptive Fuzzy Control Technology for Automatic Oil Drilling System

The paper proposes an adaptive fuzzy control method for the new oil rigs of ZJ30DB series with AC frequency converters. The assistant motor and its gearing work as executing system. Considering the time-delay, time-variability and nonlinearity of controlled objects, we design a double-loop control system in order to control the drill pressure tending to an expected value. Because it is very difficult to model the system accurately, we use a fuzzy control method in the outer loop based on the experience of skilled drillers. Since the simple fuzzy control algorithm is not able to adapt itself to the system changes momentarily, we select an adaptive fuzzy control algorithm. The inner loop is also a negative feedback loop, where the motor rotation speed signal from a sensor is fed back to the input. This can make the system response changes more quickly and more steadily. In addition, we simply study the state estimation problem based on particle filters. The scheme and the research may be beneficial to automatic drilling of oil rigs both in theory and in technology.