scholarly journals Coupling Analysis and Cross-Feedback Control of Three-Axis Inertially Stabilized Platform with an Active Magnetic Bearing System

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Tong Wen ◽  
Biao Xiang ◽  
Waion Wong
Keyword(s):  
Feedback Control ◽  
Vibration Isolation ◽  
Base Plate ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Single Input Single Output ◽  
Control Scheme ◽  
Amb System ◽  
Stabilized Platform ◽  
Inertially Stabilized Platform

An active magnetic bearing (AMB) system is used to suspend the yaw gimbal of three-axis inertially stabilized platform (ISP) to minimize the friction. The dynamic functions of three gimbals in ISP are developed. The base coupling at dynamic base plate is stronger than that at static base plate, and the gimbal coupling among three gimbals increases with the number of unlocked gimbals. Therefore, a cross-feedback control scheme is designed to minimize the base coupling and the gimbal coupling, and then the multi-input multioutput system of three-axis ISP with coupling terms is simplified into three decoupled single-input single-output systems. Experimental results verify that the yaw gimbal suspended by AMB system has better vibration isolation ability than the roll gimbal supported by mechanical bearing, and the gimbal coupling and the base coupling are effectively suppressed by the cross-feedback control scheme.

An anti-windup control strategy to actuator saturating input voltage for active magnetic bearing system

2016 ◽  
Vol 35 (3) ◽  
Author(s):  
Avadh Pati ◽  
Richa Negi
Keyword(s):  
Control Strategy ◽  
Pid Control ◽  
Input Voltage ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Region Of Attraction ◽  
Control Scheme ◽  
Amb System ◽  
Voltage Saturation ◽  
Bearing System

Purpose The active magnetic bearing is highly nonlinear and unstable system. In general most of physical systems, conventional PID control strategies are employed for their stable operation but the dynamics of the system are influenced by input voltage saturation that degrades the performance of the system. The conventional PID control scheme does not work properly alone. In such a situation, PID faces windup phenomenon that leads to instability in the system. To overcome this problem, an anti-windup control scheme leads to stable and smooth operation of active magnetic bearing system. Design/methodology/approach The proposed anti-windup control strategy is based on dynamic output feedback that is applied on linearized active magnetic bearing (AMB) system to stabilize and avoid the input voltage saturation effect in the actuator. Findings An anti-windup controller is designed for active magnetic bearing system in presence of input voltage saturation. The stability of AMB system with anti-windup controller is derived in sense of Lyapunov and expressed as linear matrix inequality problem for AMB system and the designed anti-windup controller also enlarges the region of attraction of considered AMB system. Originality/value T-S fuzzy technique is used for obtaining local linear model of nonlinear active magnetic bearing system for easy and simple implementation of anti-windup control scheme. In proposed methodology the region of attraction for anti-windup compensator is also discussed. The effectiveness of proposed method is verified by the numerical simulation results for considered active magnetic bearing system and domain of attraction or stability region of closed loop AMB system are also calculated using Eigen Value Optimization technique for both the cases such as with and without anti-windup controller. The comparative result and the contribution of proposed control strategy are also discussed.

Robust control of an active magnetic bearing system using H∞ and disturbance observer-based control

2015 ◽  
Vol 23 (11) ◽  
pp. 1857-1870 ◽  
Author(s):  
Amin Noshadi ◽  
Juan Shi ◽  
Wee Sit Lee ◽  
Peng Shi ◽  
Akhtar Kalam
Keyword(s):  
Disturbance Observer ◽  
Hybrid Control ◽  
Industrial Applications ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Control Scheme ◽  
Bounded Disturbances ◽  
Improved Performance ◽  
Amb System ◽  
Hybrid Control Scheme

Active magnetic bearing systems (AMBs) have many potential industrial applications where extremely fast and accurate operations are required. However, AMBs are often subject to disturbances in the form of synchronous vibrations due to unmodeled dynamics such as the rotor mass-imbalance and centrifugal forces while the rotor is in rotation. Several methods such as variable notch filters, gain scheduling controllers, and linear parameter varying controllers have been proposed recently to reject the disturbances while the system is operating at high rotational speeds. These methods are practical only if the frequencies of these sinusoidal-like disturbances are directly measurable or accurately known in advance. In this paper, a hybrid control scheme comprised of a feedback H∞ controller and an inner-loop disturbance observer-based control is proposed. The effectiveness of this control scheme is verified by simulation and real-time experiments on an AMB system. Both constant and sinusoidal disturbances are taken into consideration while the rotor is stationary as well as while it is rotating at different speeds. The results demonstrate that the proposed hybrid control scheme exhibits significantly improved performance in comparison to single-loop controllers in the presence of unknown but bounded disturbances.

Cancelling Gyroscopic Effects in AMB Systems With Flexible Rotors via Modal Feedback

2019 ◽  
Author(s):  
Alican Sahinkaya ◽  
Jerzy T. Sawicki
Keyword(s):  
Feedback Control ◽  
Controller Design ◽  
Sensory Information ◽  
Magnetic Bearing ◽  
Open Loop ◽  
State Feedback Control ◽  
Active Magnetic Bearing ◽  
Flexible Rotors ◽  
Amb System ◽  
Gyroscopic Effects

Abstract For active magnetic bearing (AMB) systems with rotors having significant polar to transverse moments of inertia ratio, the influence of gyroscopic effects needs to be considered in controller design procedures to prevent excessive vibrations and potential instability during operation. This consideration leads to conservative controllers due to large uncertainties caused by the rotational speed range of the rotor, or gain-scheduled controllers that require larger computational power, both of which are not desirable. A cross-feedback control has been applied in the literature to compensate for the gyroscopic effects of AMB systems with rigid rotors. However, the method is not applicable to AMB systems with flexible rotors due to lack of full-state sensory information and under actuation. This paper proposes a novel modal state feedback control as an addon controller for AMB systems with flexible rotors to compensate for the gyroscopic effects of selected modes. The aim of the add-on controller is to alter the open loop AMB system such that the open loop dynamics presents reduced gyroscopic effects of the selected modes from a controller point of view, reducing the uncertainties in the model for robust controller design. The proposed approach is demonstrated on an AMB rotor test rig with a rotor configuration featuring noticeable gyroscopic effects. The comparison of the frequency response data of the open loop AMB system with and without the proposed add-on controller shows the feasibility of the approach.

Design of backstepping control with CNN-based compensator for active magnetic bearing system subjected to input voltage saturation

2018 ◽  
Vol 15 (6) ◽  
pp. 678-687 ◽  
Author(s):  
Avadh Pati ◽  
Richa Negi
Keyword(s):  
Input Voltage ◽  
Magnetic Bearing ◽  
Backstepping Control ◽  
Active Magnetic Bearing ◽  
Control Technique ◽  
Content Type ◽  
Single Degree ◽  
Control Scheme ◽  
Amb System ◽  
Voltage Saturation

Purpose The stability and input voltage saturation is a common problem associated with an active magnetic bearing (AMB) system. The purpose of this paper is to design a control scheme that stabilizes the single degree of freedom AMB system and also tackle the problem of input voltage saturation in the AMB system. Design/methodology/approach The proposed control technique is a combination of two separate control schemes. First, the Backstepping control scheme is designed to stabilize and control the AMB system and then Chebyshev neural network (CNN)-based compensator is designed to tackle the input voltage saturation when the system control action is saturated. Findings The mathematical and simulation results are presented to validate the effectiveness of proposed methodology for single-degree freedom AMB system. Originality/value This paper introduces a CNN-based compensator with Backstepping control strategy to stabilize and tackle the problem of input voltage saturation in the 1-DOF AMB systems.

Truncated Predictor Feedback Control for Active Magnetic Bearing Systems With Input Delay

2016 ◽  
Vol 24 (6) ◽  
pp. 2182-2189 ◽  
Author(s):  
Se Young Yoon ◽  
Long Di ◽  
Parinya Anantachaisilp ◽  
Zongli Lin
Keyword(s):  
Feedback Control ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Input Delay

Some Nonlinear Effects of Magnetic Bearings

1999 ◽  
Author(s):  
Norbert Steinschaden ◽  
Helmut Springer
Keyword(s):  
Equations Of Motion ◽  
Period Doubling ◽  
Path Following ◽  
Nonlinear Effects ◽  
Magnetic Bearing ◽  
Operating Conditions ◽  
Active Magnetic Bearing ◽  
Nonlinear Phenomena ◽  
Amb System ◽  
Large Rotor

Abstract In order to get a better understanding of the dynamics of active magnetic bearing (AMB) systems under extreme operating conditions a simple, nonlinear model for a radial AMB system is investigated. Instead of the common way of linearizing the magnetic forces at the center position of the rotor with respect to rotor displacement and coil current, the fully nonlinear force to displacement and the force to current characteristics are used. The AMB system is excited by unbalance forces of the rotor. Especially for the case of large rotor eccentricities, causing large rotor displacements, the behaviour of the system is discussed. A path-following analysis of the equations of motion shows that for some combinations of parameters well-known nonlinear phenomena may occur, as, for example, symmetry breaking, period doubling and even regions of global instability can be observed.

Dynamic Modeling and Analysis of Active Magnetic Bearings

2014 ◽  
Vol 494-495 ◽  
pp. 685-688
Author(s):  
Rong Gao ◽  
Gang Luo ◽  
Cong Xun Yan
Keyword(s):  
Dynamic Characteristic ◽  
Dynamic Modeling ◽  
Magnetic Bearing ◽  
Integrated System ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Active Magnetic Bearings ◽  
Modeling And Analysis ◽  
Amb System ◽  
Mathematics Method

Active magnetic bearing (AMB) system is a complex integrated system including mechanics, electronic and magnetism. In order to research for the basic dynamic characteristic of rotor supported by AMB, it is necessary to present mathematics method. The dynamics formula of AMB is established using theory means of dynamics of rotator and mechanics of vibrations. At the same tine, the running stability of rotor is analyzed and the example is presented in detail.

scholarly journals Nonlinear Vibrations of a Rotor-Active Magnetic Bearing System with 16-Pole Legs and Two Degrees of Freedom

2020 ◽  
Vol 2020 ◽  
pp. 1-29 ◽  
Author(s):  
W. Zhang ◽  
R. Q. Wu ◽  
B. Siriguleng
Keyword(s):  
Perturbation Method ◽  
Electromagnetic Force ◽  
Nonlinear Vibrations ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Time Varying ◽  
Asymptotic Perturbation Method ◽  
Amb System ◽  
Asymptotic Perturbation ◽  
Quadratic And Cubic Nonlinearities

The asymptotic perturbation method is used to analyze the nonlinear vibrations and chaotic dynamics of a rotor-active magnetic bearing (AMB) system with 16-pole legs and the time-varying stiffness. Based on the expressions of the electromagnetic force resultants, the influences of some parameters, such as the cross-sectional area Aα of one electromagnet and the number N of windings in each electromagnet coil, on the electromagnetic force resultants are considered for the rotor-AMB system with 16-pole legs. Based on the Newton law, the governing equation of motion for the rotor-AMB system with 16-pole legs is obtained and expressed as a two-degree-of-freedom system with the parametric excitation and the quadratic and cubic nonlinearities. According to the asymptotic perturbation method, the four-dimensional averaged equation of the rotor-AMB system is derived under the case of 1 : 1 internal resonance and 1 : 2 subharmonic resonances. Then, the frequency-response curves are employed to study the steady-state solutions of the modal amplitudes. From the analysis of the frequency responses, both the hardening-type nonlinearity and the softening-type nonlinearity are observed in the rotor-AMB system. Based on the numerical solutions of the averaged equation, the changed procedure of the nonlinear dynamic behaviors of the rotor-AMB system with the control parameter is described by the bifurcation diagram. From the numerical simulations, the periodic, quasiperiodic, and chaotic motions are observed in the rotor-active magnetic bearing (AMB) system with 16-pole legs, the time-varying stiffness, and the quadratic and cubic nonlinearities.

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