Mrinal Kanti Sarkar

A Review Note on Different Components of Simple Electromagnetic Levitation Systems

Abstract Electromagnetic levitation is an important area of research. There is lot of applications of maglev in industry. Extensive research is going on for the last two decades throughout the world to design the latest form of the maglev system. Due to interdisciplinary nature, many aspects are still open in maglev research. The major components in an electromagnetic suspension system are (i) actuator, (ii) sensor, (iii) controller, and (iv) power amplifier. For the successful implementation for any maglev-based project, the basic knowledge of these components is necessary. In this manuscript, an extensive review of different components of electromagnetic levitation systems has been presented.

Evolutionary computation based optimization of controller parameters for an Electromagnetic Levitation System

In this paper the optimized parameters of Lag-Lead and Proportional Integral Derivative (PID) controller for two-actuator based electromagnetic levitation system (EMLS) are determined using Evolutionary computation algorithms such as Particle Swarm Optimization (PSO) and a novel Gravitational Search algorithm (GSA). A comparative position response of EMLS (Electro Magnetic Levitation System) with classical, GSA and PSO based nominal controllers while operating at nominal and off-nominal (low and high) air-gaps have been studied. It is seen that GSA based optimized nominal PID controller shows excellent performance (both in transient and steady-state) over a large operating air-gap. The experimental results with the classical controller are also presented.

Adaptive fuzzy parameter scheduling scheme for GSA based optimal Proportional Integral Derivative and lag-lead control of a DC Attraction type Levitation System

Magnetic levitation system is inherently unstable and strongly nonlinear in nature. Fixed optimal gain controllers designed at some nominal operating conditions fail to provide the best control performance over a wide range of off-nominal operating conditions. In this paper, an adaptive fuzzy parameter scheduling scheme for Gravitational Search Algorithm (GSA) based optimal Proportional Integral Derivative (PID) and Lag-Lead controllers has been proposed to control a single actuator based DC Attraction type Levitation System (DCALS). A Takagi-Sugeno (T-S) fuzzy inference system is used in the proposed controllers. The inference system is extremely well suited to the task of smoothly interpolating linear gains across the input space when a strongly non-linear DCALS moves around in its operating space. Simulation results show that both proposed adaptive fuzzy PID and Lag-Lead controllers offer better performance than fixed gain controllers at different operating conditions.

DSP based implementation of piecewise linear control scheme for wide air-gap control of an electromagnetic levitation system

Electromagnetic levitation system (EMLS) is inherently unstable and strongly non-linear in nature. In majority cases the closed loop system has been stabilized by classical controller utilizing linearlized model of EMLS. The linear classical controller has a restricted zone of operation. But it is essential to design a control scheme so that EMLS can operate for a large air-gap stably and at the same time the performance of controller will be satisfactory irrespective of any change in operating air-gap. This paper reports design, implementation and testing of piecewise linear control schemes to extend the range of operating air-gap for a voltage controlled (EMLS) in real time environment through dSPACE.

Optimization of controller parameters for a DC attraction type levitation system by evolutionary technique

In this paper, evolutionary computation algorithms such as a novel Gravitational Search algorithm (GSA) and Real Coded Genetic Algorithm (RGA) are used to optimize the parameters of PID controller for a single actuator based DC attraction type levitation system (DCALS). A comparative study between performances of classical, GSA and RGA based nominal PID controller while operating at nominal and off-nominal (low and high) air-gaps has been carried out. It is seen that the GSA based optimized nominal PID controller produces best performances for the proposed DCALS with a wide variation of operating air-gaps.

A practical demonstration for simultaneous suspension and rotation for a ferromagnetic object-an application of DC electromagnetic levitation

In this paper a practical demonstration for simultaneous lévitation and rotation for a ferromagnetic object is presented. A hollow steel cylinder of 59 gm mass is arranged to remain suspended stably under I-core electromagnet utilizing DC electromagnetic levitation principle and then arranged to rotate the levitated cylinder around 1000 rpm speed based on eddy current based energy meter principle. Since the object is to be rotating during levitated condition the device will be frictionless, energy-efficient and robust. This technology may be applied to frictionless energy meter, wind turbine, machine tool applications, precision instruments and many other devices where easy energy-efficient stable rotation will be required. The cascade lead compensation control scheme has been applied for stabilization of unstable levitation system.

Analysis, design, fabrication and testing of three actuators based electromagnetic levitation system for vehicle applications

In this paper the analysis, design and fabrication of 3-coil based DC attraction type levitation scheme has been presented. In vehicle applications majority works have been reported based on four actuators based electromagnetic levitation system (EMLS). But in this prototype three electromagnets have been used at the three sides of the platform. The use of one magnet-coil, power amplifier and associated gate driver, controller circuit, position and current sensor is dispensed with the prototype. So there is considerable reduction of cost and weight of the proposed system and the hardware circuit is also simpler than four-coil structure. The objective is to levitate a platform under ferromagnetic guide-way normally used in electromagnetically levitated vehicle structure. The prototype (total mass 7.528kg) consists of three identical electromagnets placed at the three sides of a platform and the structure is made to remain suspended at different air-gap positions under a ferromagnetic guide-way - the arrangement that is normally used for EMLS. The structure of the levitated system has been constructed in-house. The three actuators have been controlled simultaneously by three similar single input single output (SISO) controllers utilizing the cascade Lead compensation control scheme. The design and implementation of the controller for such an unstable and non-linear system is the main aim of this study. The stable levitation has been demonstrated of the platform around an operating point.

Genetic Algorithm Based Optimization of Controller Parameters for an Electromagnetic Levitation System

Electromagnetic levitation system (EMLS) is inherently unstable and strongly non-linear in nature. Controllers based on linear model and designed by classical approach for any EMLS have restricted zone of operation. For a small variation of operating air-gap there is sharp degradation of controller performance. But it is essential to design an optimized controller that will stabilize unstable EMLS and will provide satisfactory performance for a wide range of operating air-gap. In this paper a Genetic Algorithm (GA) based optimisation technique for controllers of two actuator based levitation system has been discussed. GA has a highly proven track record of optimisation of parameters for different types of control schemes. Here the work focuses mainly on an optimal control of a proposed two actuator based EMLS scheme, which is composed of a stochastic technique based on Genetic Algorithm (GA).