Investigation of a 2-DOF Active Magnetic Bearing Actuator for Unmanned Underwater Vehicle Thruster Application

Abstract

In this work, a novel application of Active Magnetic Bearing (AMB) is proposed to integrate AMB in the Magnetically Coupled Thruster (MCT) assembly for underwater application. In this study, a 2-Degree-Of-Freedom (DOF) AMB is developed and investigated for the MCT of an Unmanned Underwater Vehicle (UUV). The paper presents the detailed electro-mechanical modeling of the in-house developed AMB system. The intractable problem of rotor suspension and rotation with opposing pairs of electromagnets is considered. A Linear Quadratic Gaussian (LQG) controller is designed and analyzed in the frequency domain for the stabilization of the open-loop unstable AMB for MCT. The performance specifications of the controller, such as reference tracking and disturbance rejection are achieved and evaluated through real-time implementation of the controller. The compensator also performed reasonably well during the dynamic operations, i.e., when the rotor-propeller assembly was spun at 1500 rpm. This rotor speed is needed to generate a thrust of 40–45 N and up to 1 m/s forward velocity, which is necessary to propel the UUV under consideration. By deploying AMB in MCT assembly, it is anticipated that problems associated with the conventional directly coupled thruster operating in harsh underwater environment, such as water ingress into electronics compartment, rusting, lubrication, and vibrations would be eliminated.

Advanced Power Generation Using a Nitrogen Turbine Engine Instead of a Conventional Injection Steam Turbine Engine

“…It is also crucial to apply magnetic bearings to the centrifugal axle shaft system and turbines as this will not cause pollutants. Magnetic bearings do not require lubrication, nor do they touch the centrifugal axle shaft (zero touch) [66,75]. A firm in Japan and the United States suggested that the installation of magnetic bearings to compressor technology of centrifugal chillers can save costs up to 42.3-50%/year [76][77][78].…”

The Influence of Magnetic Field of AMB on Eddy-Current Sensor Operation

“…The magnetic support system of a high-speed machine rotor usually consists of an electromechanical actuator, a control unit, amplifiers and sensors [ 15 , 16 , 17 , 18 , 19 , 20 ]. The electromechanical actuator is intended to support a high-speed rotor and generate electromagnetic force, providing its stable operation.…”

“…Two types of sensors are typically used in the AMB systems, namely induction sensors and displacement sensors. Induction sensors have good potential but are difficult to use because they must be mounted in the bearing air gap [ 17 , 18 ]. On the other hand, displacement sensors are more expensive and introduce some design limitations, but their configuration and assembly are simpler than in the case of induction sensors.…”

An Improved Vicsek Model of Swarms Based on a New Neighbor Strategy Considering View and Distance

“…Modeling is developed to understand collective behaviors in nature better, as well as to effectively control artificial swarms, such as multi-robot systems [8] and unmanned vehicles [9][10][11]. Reynolds proposed the Boid model and ran the first computer simulation of flocking based on three heuristic rules, known as cohesion, separation, and alignment [12].…”