Avadh Pati and Richa Negi
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…
Abstract
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.
Details
Keywords
Avadh Pati and Richa Negi
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…
Abstract
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.
The purpose of this paper is to identify the issues and challenges in humanitarian logistics and to develop a framework for effectively managing the humanitarian logistics in…
Abstract
Purpose
The purpose of this paper is to identify the issues and challenges in humanitarian logistics and to develop a framework for effectively managing the humanitarian logistics in disaster relief supply chain operations in India.
Design/methodology/approach
This paper presents a framework to manage humanitarian logistics effectively in disaster management through qualitative analysis. First, the author examines the challenges facing the humanitarian logistics and supply chain through the reviews of the literature on various disasters. Then, the author presented a framework based on the best practices and initiatives taken worldwide in the preparedness and response stage of the humanitarian supply chain to manage and reduce the aftermath of any disaster in context to India.
Findings
A framework has been developed to manage humanitarian logistics in the disaster relief operation, which would improve the humanitarian supply chain in India and help to effectively manage natural disasters in the preparedness and response stage at the state and district levels.
Research limitations/implications
The paper mainly emphasises on the preparedness and response stage of disaster supply chain management in Indian context.
Practical implications
None of the disaster incidents can be stopped from taking place, but the impact can be minimised by proper preparedness and effective response during the operations of humanitarian logistics. With this hope, the framework has been developed, which if implemented would help to plan and manage any disaster incident in an effective manner, which ultimately would save millions of lives and cost in terms of infrastructure, property, assets etc.
Originality/value
As natural disaster incidents are occurring frequently in Indian states, there is an urgent need for a framework to manage the logistics operations effectively and efficiently during any disaster relief operations. Limited literature is found on developing and presenting a framework focusing on the preparedness and response phase of disaster supply chain management in context to India. Hence, this paper is believed to be the first to fulfil this gap with main emphasis on the preparedness and response stage of disaster supply chain management in Indian scenario.