Modeling and optimal design of relative position detection sensor for high speed maglev train
TL;DR: In this paper, the influence of the eddy current induced in the windings on the coil inductance was studied, and a method of no-load voltage compensation and an optimal sensor excitation frequency was proposed to improve the accuracy of the sensor.
Abstract: The long stator track for high speed maglev train has a special tooth-slot structure. The relative position detection sensor obtains precise relative position information for the operation control system by detecting the changing coil inductance reflecting the long stator tooth-slot structure. The aluminum windings are inlaid in the stator slots, and the magnetic field due to the sensor coils induces eddy current in them, which would change the magnetic field distribution and have a significant influence on the sensor. In this paper, the multipole theory (MT) is adopted to build the analytical electromagnetic model of the sensor. Based on the electromagnetic model, the influence of the eddy current induced in the windings on the coil inductance is studied. The DC offset formula of differential voltage owing to the slight inductance difference of the coils is derived. The influence of the eddy current on the DC offset is analyzed, based on which, a method of no-load voltage compensation and an optimal sensor excitation frequency is proposed to improve the accuracy of the sensor.
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01 Aug 2017
TL;DR: In this article, an approach to decouple the suspension height and displacement of relative position detection sensor is proposed, which can greatly improve the position precision and accuracy of the position detection system.
Abstract: Aiming at the problem that position measurement precision of relative position detection sensor is influenced by the fluctuation of suspension height, an approach to decouple the suspension height and displacement is proposed. Firstly, the relationship between the suspension height and output signals of sensor is founded, by analyzing the working principles and signal processing flow. And then, suspension height and displacement decoupling method is proposed. At last, a comparison experiment is presented, whose results prove that this approach can greatly improve the location precision and accuracy.
7 citations
Cites background from "Modeling and optimal design of rela..."
...In addition, it also provides accurate speed information for the operation control system [4]....
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TL;DR: The proposed solution can effectively adapt to various conditions of vehicle operation, overcome the influence of electromagnetic interference and suspension fluctuations, and realize the high-precision positioning requirements of high-speed Maglev trains.
6 citations
28 Apr 2016
TL;DR: The fuzzy model system based on GDA is applied to ensure the effectiveness of tracking performance by replacing the mathematical model of MLS, and an auxiliary supervisory control effort is added to promote its performance under larger external disturbance.
Abstract: Magnetic levitation system (MLS), using the electromagnetic force to float, can effectively reduce the mechanical vibration friction and wearing loss caused by contact operation. However, the parameters in the mathematical model are related to the permanent magnet geometry, distance and the total mass of the platform. To achieve good tracking performance, a fuzzy system and the parameter identification algorithm for maglev suspension system are proposed in the paper. The proposed fuzzy model method is to establish a common fuzzy system procedure. By using the gathered data pairs, the parameters of membership functions are updated through gradient descent algorithm (GDA). In this paper, the fuzzy model system based on GDA is applied to ensure the effectiveness of tracking performance by replacing the mathematical model of MLS. Furthermore, to promote its performance under larger external disturbance, an auxiliary supervisory control effort is added. Thus, the chattering phenomenon is reduced and fast response can be obtained without degrading the tracking performance of the system dynamic. Some simulated and experimental results are provided to verify the feasibility and effectiveness of the proposed system.
6 citations
Cites background from "Modeling and optimal design of rela..."
...Nowadays, magnetic levitation systems (MLS) have been broadly implemented for a lot of fields in our daily lives, such as maglev transportation (or magnetic levitation transportation), magnetic bearings, levitation of wind tunnel models, vibration isolation, and fast-tool servo system [1-6]....
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TL;DR: In this article , an efficient eddy current speed sensor with high sensitivity and fault-tolerant capability using novel pickup coil configurations has been presented, which has one rectangular excitation coil and two sets of pickup coils for voltage measurement.
Abstract: This paper presents a novel eddy current speed sensor for linear speed measurement of moving flat iron parts. The main goal of the paper is to present an efficient eddy current speed sensor with high sensitivity and fault-tolerant capability using novel pickup coil configurations. It has one rectangular excitation coil and two sets of pickup coils for voltage measurement. The first set of pickup coils consists of eleven serially connected coils, which are perpendicularly mounted and arranged on top of the excitation coil in a transversal direction. The second set of pickup coils comprises two antiserially connected pickup coils that are in the same longitudinal direction as the excitation coil. The measurements of the sensor are performed up to ± 17.9 m/s (64 km/h) at excitation frequencies of 1000 Hz and 4000 Hz. Analytical calculations are used for the parametric and performance analyses of the eddy current speed sensor. The calculation results are compared with the measurements. The sensor's nonlinearity error is 1%. The performance of the sensor is also assessed for a higher speed range, up to 600 km/h.
3 citations
01 Oct 2017
TL;DR: A signal process algorithm based on KF-UKF and a state space model for the relative position detection sensor are proposed, which can estimate the position and speed of maglev trains, even when lots of Gaussian noises exits.
Abstract: The relative position detection sensor can detect the tooth-slot structure of long stator track and generate periodic sinusoid signals. A signal process algorithm based on KF-UKF and a state space model for the sensor are proposed in this paper, which can estimate the position and speed of maglev trains, even when lots of Gaussian noises exits. Actual comparison experiments and numerical simulations demonstrate the performance of the proposed algorithm is better than others, meanwhile with a lower computation complexity, which can satisfy the requirement of actual applications.
3 citations
References
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TL;DR: The magnetic sensors based on the giant magneto resistance (GMR) effect developed for position detection are now finding their way into industrial and automotive applications as discussed by the authors, and they overcome a weakness in conventional magnetoresistors and Hall sensors, because they are less sensitive to air gap deviations apparent in many applications.
Abstract: Magnetic sensors are ideal for all kinds of contactless position registration, e.g. distance, speed, angle, rotational speed and sense of rotation. They work even under adverse and dirty environmental conditions. These basic advantages have resulted in the widespread use of all kinds of magnetic sensors in contactless position detection. The magnetic sensors based on the giant magneto resistance (GMR) effect developed for position detection are now finding their way into industrial and automotive applications. They overcome a weakness in conventional magnetoresistors and Hall sensors, because they are less sensitive to air gap deviations apparent in many applications. This paper presents the basic concepts of GMR sensors for contactless position detection. The advantages of the sensor and relevant examples for industrial and automotive applications are discussed.
74 citations
TL;DR: In this article, an analytical algorithm for calculating the inductance of planar multi-wire coils with arbitrary number of parallel wires and layers is presented, based on an integral solution starting from Biot-Savart's law and allowing a fast calculation of the coil inductance.
Abstract: This paper describes for the first time an analytical algorithm for calculating the inductance of planar multi-wire coils with arbitrary number of parallel wires and layers. The special topology of multi-wire coils, with many parallel wires connected at both endings, allows efficient telemetric energy transfer and low Joule losses due to a reduced DC resistance. The algorithm is based on an integral solution starting from Biot–Savart's law and allows a fast calculation of the coil inductance. The algorithm is verified with a large number of fabricated and measured coils with inductance values ranging from 45 nH to 10 μH. The small coils are microfabricated on a polyimide foil with electroplated gold wires. The larger coils are realized on a printed circuit board. The coils have up to seven parallel wires and two layers. The inductance is measured at 1 MHz and shows good agreement to the calculation results. The error between calculation and measurement is less than 10% and proves the correctness of the presented algorithm.
43 citations
TL;DR: In this article, the second-order vector potential (SOVP) formulation is used to treat the problem by reducing it to the solution of the scalar field equation, while the analytical solution is expressed in terms of known orthogonal expansions, the numerical solution utilizes the finite difference method.
Abstract: The three-dimensional (3-D) eddy-current problem, described in spherical coordinates, is studied both analytically and numerically. Since the vector field equation is not separable in the spherical coordinate system, the second-order vector potential (SOVP) formulation is used to treat the problem by reducing it to the solution of the scalar field equation. While the analytical solution is expressed in terms of known orthogonal expansions, the numerical solution utilizes the finite difference method. Examples of engineering applications are provided, concerning computation of eddy-current distribution in a conducting sphere by a filamentary excitation of arbitrary shape.
37 citations
TL;DR: In this article, a multipole theory (MT) method is presented for calculating two-dimensional (2-D) Helmholtz equation problems, and the general MT formula and its applied laws are derived.
Abstract: A new approach, the multipole theory (MT) method, is presented for calculating two-dimensional (2-D) Helmholtz equation problems. By the mathematical deduction, the general MT formula and its applied laws are derived. The new approach has been applied to compute the cutoff wavenumbers of a rectangular waveguide, as analytical results are available for this problem. In order to further verify the accuracy of this method, the MT method has also been applied to compute the TE and TM modes of two high power waveguides and a square offset line. Comparison of accuracy is made whenever data is available. It has been proven that the MT method is an effective approach for calculating 2-D Helmholtz equation problems.
17 citations
TL;DR: In this article, the distribution of eddy (or Foucault)-current stream lines induced within a conducting slab of a non-magnetic material when crossing, with a constant velocity and perpendicularly, a permanent magnetic field was studied.
Abstract: The present work aims to study the distribution of eddy (or Foucault)-current stream lines induced within a conducting slab of a non-magnetic material when crossing, with a constant velocity and perpendicularly, a permanent magnetic field. The computation of the magnetic field induced by these currents will also be performed. The purpose of this study is to provide a basic theoretical background to be used in the development of a new transducer.
14 citations