Reverse Overshoot Suppression in a Managed Pressure Drilling Control System

Abstract

Automatic feedback control systems provide the highest control accuracy in all engineering and technology fields. It applies both to static and dynamic accuracy. If the object is prone to oscillations and also contains a significant delay, then it may be an initial movement in the opposite direction in the transition process. Here the output changes in the opposite direction to the required. Such behavior of the transition process may be unacceptable in many tasks, although the final movement can be achieved in the right direction and by the desired increment. It means the static error can be made negligible. There are many objects prone to oscillations in nature and technology. These are actuators on string suspensions, an inverted pendulum, especially with many plants, the robotic vehicles, etc. Among the many practical problems in the paper we consider the class of Managed Pressure Drilling Control System and logging during drilling, where is a strong tendency to fluctuations. But this is also a characteristic feature of many technological processes. Unfortunately, attention is rarely paid to eliminate a reverse overshoot among indicators of dynamic accuracy in these systems. Many textbooks for a regulator design even do not mention this characteristic due to rare appearances. However, reverse overshoot is one of the most critical indicators of dynamic accuracy. This paper solves the problem of the reverse overshoot suppressing for control of the most complex dynamic objects based on analysis of the various methods of controller design and method of numerical optimization. Additional techniques have been found that allow the most effective solution. It has been tested by simulation modeling corresponding to the tasks of managed well drilling.