Feedback Linearization using High Gain Observer for Nonlinear Electromechanical Actuator

Naval applications need refined regulation, to meet modern era standards, which eventually leads to the requirement of more accurate mathematical modeling of all subsystems. All naval autonomous systems are equipped with electromechanical actuators, which are often controlled for linear operating range and nonlinearities which may lead to chaotic behavior, are ignored. Additionally, the necessary use of observers for the linear model limits the level of autonomy. In this paper, a typical solenoid actuator is studied with the inclusion of third-order nonlinear dynamic properties. A nonlinear output feedback control is designed for tracking the position of the plunger in solenoid actuator. High gain observer (HGO) is realized to estimate the unknown states. The proposed topology for solenoid actuator uses feedback linearization along with the HGO to achieve the performance of state feedback control which solidifies the effectiveness of HGO. The results are obtained using MATLAB/ SIMULINK.

I. Introduction

In recent years, the automation of naval machinery has been fixated a lot with the goal of being capable of acquiring prediction of the system's behavior. It would eventually lead to a higher level of autonomy than it is nowadays. Sensors, actuators, controllers, communication systems, cabling and piping are some of the compulsory parts of an autonomous naval system [1]. Efficient autonomous machinery requires intelligent actuating valves, introduced as “smart valves” in modern-day literature. There are many types of actuator valves that are being used. Gate valves, globe valves, check valves and butterfly valves are among the most commonly used valves for naval machinery. For intelligent operation, each valve is equipped with some electromechanical actuation. A Typical butterfly valve provides actuation by a solenoid actuator, which is studied in this research [2].