Coupling vibration analysis of high-speed maglev train-viaduct systems with control loop failure

The risk of failure of the control loop can occur when a high-speed maglev train runs on viaduct.Meanwhile,the failure of the levitation magnets which balances the gravity of the maglev train could cause the train collision with track.To study the dynamic response of the train and the viaduct when the levitation magnet control loop failure occurs,a high-speed maglev train-viaduct coupling model,which includes a maglev controller fitted by measured force-gap data and considers the actual structure of train and viaduct,is established.Then the accuracy and effectiveness of the established approach are validated by comparing the computed dynamic responses and frequencies with the measurement results.After that,the dynamic responses of maglev train and viaduct are discussed under normal operation and control loop failures,and the most disadvantageous combination of control loop failures is obtained.The results show that when a single control loop fails,it only has a great influence on the failed electromagnet,and the maglev response of adjacent electromagnets has no obvious change and no collision occurs.But there is a risk of rail collisions when the dual control loop fails.

Control strategy of maglev vehicles based on particle swarm algorithm

Taking a single magnet levitation system as theobject, a nonlinear numerical model of the vehicle–guidewaycoupling system was established to study the levitationcontrol strategies. According to the similarity in dynamics,the single magnet-guideway coupling system was simplifiedinto a magnet-suspended track system, and the correspondinghardware-in-loop test rig was set up usingdSPACE. A full-state-feedback controller was developedusing the levitation gap signal and the current signal, andcontroller parameters were optimized by particle swarmalgorithm. The results from the simulation and the test rigshow that, the proposed control method can keep the systemstable by calculating the controller output with the fullstateinformation of the coupling system, Step responsesfrom the test rig show that the controller can stabilize thesystem within 0.15 s with a 2 % overshot, and performswell even in the condition of violent external disturbances.Unlike the linear quadratic optimal method, the particleswarm algorithm carries out the optimization with thenonlinear controlled object included, and its optimizedresults make the system responses much better.

H infinity Control for Sandwiched Maglev Stage with Dynamic Damping

An H infinity(H∞)controller for a sandwiched maglev positioning stage is proposed.The maglev positioning stage has a special structure:a sandwiched maglev stage,consisting of repulsive linear motors and attractive linear motors,which have better levitation performance.Forces on the sandwiched maglev stage are analyzed and modeled.The positioning controller is designed based on the feedback linearized model with a dynamic damping system.The design of the H infinity controller for stage positioning is derived as a series of linear matrix inequalities(LMIs)which are efficiently solved in Matlab.The proposed controller and its effectiveness is demonstrated compared to PID method.

Research on the H_∞ Controller Synthesis for Maglev Suspension System

The performances of a single magnet model, which is the simplified model of Maglev suspension, are analyzed. The H ∞ controller synthesized for the single magnet model is presented. The synthesis results show that the control performance and robustness performance are satisfactory and the application of the H ∞ controller to Maglev suspension is feasible and effective.

Sliding Mode Control with Auto-Tuning Law for Maglev System

This paper presents a control strategy for maglev system based on the sliding mode controller with auto-tuning law. The designed adaptive controller will replace the conventional sliding mode control (SMC) to eliminate the chattering resulting from the SMC. The stability of maglev system is ensured based on the Lyapunov theory. Simulation results verify the effectiveness of the proposed method. In addition, the advantages of the proposed controller are indicated in comparison with a traditional sliding mode controller.

A nonlinear control method for the electromagnetic suspension system of the maglev train

To deal with the inherent nonlinearity and open-loop instability of the electromagnetic suspension（EMS） system,a new nonlinear control method is proposed.The simulation results show that,for a PID controller,the over-shoot of the system response to an airgap step disturbance is about 3 mm,and the transient time is 6 s;however,for the proposed nonlinear controller,there is no overshoot and transient time within 2 s.The proposed method has a faster response and stronger robustness.With a designed bi-DSP suspension controller,this nonlinear control method was implemented on the Shanghai Urban Maglev Test Line（SUMTL） to validate its effectiveness and feasibility.

Adaptive backstepping control for levitation system with load uncertainties and external disturbances

To explore the precise dynamic response of the levitation system with active controller, a maglev guide way-electromagnet-air spring-cabin coupled model is derived firstly. Based on the mathematical model, it shows that the inherent nonlinearity, inner coupling, misalignments between the sensors and actuators, load uncertainties and external disturbances are the main issues that should be solved in engineering. Under the assumptions that the loads and external disturbance are measurable, the backstepping module controller developed in this work can tackle the above problems effectively. In reality, the load is uncertain due to the additions of luggage and passengers, which will degrade the dynamic performance. A load estimation algorithm is introduced to track the actual load asymptotically and eliminate its influence by tuning the parameters of controller online. Furthermore,considering the external disturbances generated by crosswind, pulling motor and air springs, the extended state observer is employed to estimate and suppress the external disturbance. Finally, results of numerical simulations illustrating closed-loop performance are provided.

μ-Syntheses of Suspension Systems for EMS and EDS Maglev Vehicles

Under model uncertainty and complex disturbance, the robust control strategy should be used in suspension control systems for various Maglev vehicles to obtain ride comfort of passengers. In this paper, the robust controllers are synthesized using μ approach for levitation system of electromagnetic Maglev vehicle and active suspension system of super conducting Maglev vehicle. The numerical simulations for different parameter perturbations and different disturbances are accomplished, and a comparison of μ control and H ∞ control is performed. The simulation results show that, both H ∞ control and μ control for two kinds of Maglev vehicles exhibit good stability robustness to plant model uncertainty, but μ control exhibits better performance robustness than H ∞ control, therefore better ride quality could be obtained by μ control.

Control of magnetic levitation positioning stage with an eddy current damper

To enhance the system damping,a permanent magnet set which served as an eddy current damper was added to the magnetic levitation positioning stage which consists of a moving table,four Halbach permanent magnetic arrays,four stators and displacement sensors.The dynamics model of this stage was a complex nonlinear,strong coupling system which made the control strategy to be a focus research.The nonlinear controller of the system was proposed based on the theory of differential geometry.Both simulation and experimental results show that either the decoupling control of the movement can be realized in horizontal and vertical directions,and the control performance was improved by the damper,verifying the validity and efficiency of this method.

基于扰动补偿的磁悬浮转台分数阶滑模控制

针对存在非线性、耦合性和不确定性的磁悬浮转台的高精度运动控制问题,提出一种基于非线性干扰观测器的分数阶滑模控制方法以提高跟踪精度.首先,基于系统电磁力模型和动态解耦方法,构建六自由度磁悬浮转台系统动力学模型;其次,设计非线性干扰观测器,对包含系统误差、六自由度间耦合项和外界干扰的集总扰动进行估计,证明了估计误差有界且可调节到任意小;然后,在离散域提出了一种分数阶滑模面,采用分数幂函数替代传统符号函数来抑制抖振,引入分数阶微积分来减小跟踪误差;最后,设计有限时间收敛的分数阶滑模控制策略,并利用李雅普诺夫稳定性理论证明闭环系统稳定性.实验结果表明:与整数阶滑模控制方法相比,采用所提方法,2个水平自由度和绕竖直方向旋转自由度对三角波的跟踪误差均方根分别减小了12.8%、16.8%和23.7%,最大跟踪误差分别减小9.26%、13.00%和33.20%;跟踪圆形轨迹时,2个水平自由度的跟踪误差均方值分别减小6.39%和12.40%,最大跟踪误差分别减小9.90%和12.10%.

Real Time Implementation of Series Expansion Based Digital Controller for Magnetic Levitation System

This paper addresses a digital controller for a real time magnetic levitation system using series expansion of pulse transfer function, which achieves desired closed loop response. The proposed digital controller designed, based on series expansion of pulse transfer function by solving a linear equation using the method of least squares, which improves the transient performance and step tracking capability of the compensated system. The designed algorithm used for the control input is not iterative, so the calculation is very fast. The proposed control scheme has successfully applied on maglev system and also validated through the simulation and hardware experimental results.

磁浮列车悬浮力的公式优化及悬浮系统的建模与实验

EMS (Electro-magnetic suspension)型中低速磁浮列车的悬浮系统在建模过程中,通常利用泰勒公式将悬浮力在平衡点处线性化。线性化后的近似悬浮力公式与标称悬浮力公式之间存在一定的误差。本文将该误差作为一种不确定性进行研究,由此得到了新的悬浮力公式并创新性地构建了具有不确定性的悬浮系统模型。随后,利用所建立的模型设计了一个基于广义内模控制算法的悬浮控制器,并在悬浮系统的单转向架平台上进行了抗干扰能力测试和过台阶能力测试。实验结果表明在本文所提出的悬浮控制器作用下,系统具有良好的悬浮性能和鲁棒性。

激光跟踪仪CFIII三维控制网数据采集软件研制

根据激光跟踪仪自身特点和实际工程应用需要,设计开发了一款激光跟踪仪CFIII三维控制网数据采集软件,该软件主要为高速磁浮、火箭撬滑轨测设一类具有特殊精度要求的测量工作提供外业数据采集服务。本文首先按照软件开发的一般流程进行需求分析和功能设计,并以此为基础对激光跟踪仪控制网测量等相关功能算法进行研究,然后对其中一些关键的功能算法进行阐述,再对各项子功能进行编码实现。最后,本文设计了一系列测量对比分析和仿真计算实验对软件各项功能进行可靠性验证,实验结果表明,本文研制的软件运行正常,测量结果正确、可靠。

高速磁浮车-桥耦合振动控制参数影响分析

磁浮列车悬浮系统控制参数取值不当可能导致车-桥系统异常振动.因此,明确悬浮系统控制参数与磁浮车-桥系统动力响应之间的关系十分重要.首先,建立包含比例-微分控制的5节编组磁浮列车动力学模型和20跨简支梁桥有限元模型;其次,与实测结果进行对比验证所建立模型的正确性;最后,计算车速430 km/h时不同控制参数下列车和桥梁的动力响应.结果表明:增大比例系数会使悬浮和导向系统刚度增大,增大微分系数会使悬浮和导向系统阻尼增大;车体竖向加速度随比例和微分系数的增大而增大,车体横向加速度随比例系数的增大而增大;悬浮间隙和桥梁竖向加速度均随比例系数的增大而减小,随微分系数的增大而增大;导向间隙随微分系数的增大而减小,比例系数对导向间隙的影响较小;桥梁横向加速度随比例系数的增大而减小,随微分系数的增大而增大;桥梁竖向加速度主要受电磁力中悬浮电磁铁长度特征频率1倍~12倍频的影响,桥梁横向加速度主要受导向磁极长度特征频率及其2倍频和导向电磁铁长度特征频率2倍频及4倍频的影响;为减小车-桥系统动力响应,综合建议竖向比例和微分系数的取值范围分别为3000~4000和10~25,横向比例和微分系数的取值范围分别为4000~5000和10~25.

基于滑模理论的城市轨道车辆稳定性自动化控制研究

针对磁悬浮车辆悬浮控制缺少同步协调、稳定性不足的问题,提出基于滑模理论并加入协同控制律的控制系统。对磁悬浮系统进行动力学分析,加入扰动观测器进行相应的扰动补偿,基于滑模理论设计出能够耦合同步协调的控制系统。通过实验与传统PID控制系统对比,结果表明,基于滑模理论的磁悬浮控制系统能够更好地避免电磁铁产生的耦合扰动,提高了车辆运行的稳定性。

磁悬浮微重力隔振系统自抗扰主动控制研究

空间站中精密仪器、敏感设备及微重力实验极易受太空微振动的干扰,非接触式磁悬浮微重力隔振系统是解决微振动的重要手段之一,主动控制对其隔振效果至关重要,是研究的核心。首先,基于磁悬浮微重力隔振平台,建立系统六自由度姿态解耦模型,构建具有外激励的耦合动力学模型;然后,提出并设计基于位移控制的“观测+补偿”自抗扰主动控制器,跟踪目标信号,观测系统的总干扰并实时补偿;其次,建立主动控制的仿真模型,分析主动控制参数对磁悬浮微重力隔振系统的影响规律;最后,对主动控制系统的性能进行仿真分析。结果表明,该微重力主动控制器具有良好的一致性和隔振性能,为磁悬浮微重力隔振系统主动控制的研究提供了一定的技术和理论支持。

车轨系统多重振动下的高精度自抗扰悬浮控制

针对常导磁浮列车的高精度悬浮控制问题,考虑悬浮电磁铁、悬浮架、车体的弹性连接结构以及含有高阶振动分量的桥梁动力学,建立车轨耦合垂向运动模型。分析从输入电压到悬浮间隙的积分器串联系统结构,给出悬浮自抗扰控制设计。同时,采用悬浮电磁铁加速度反馈设计,加快列车各部分垂向加速度振荡的衰减速度,提升舒适性。针对所提方法,给出闭环稳定性结果。针对轨道周期扰动、参数摄动情况,进行仿真验证。

中低速磁浮列车电磁线性涡流制动装置控制效能研究

[目的]线性涡流制动装置是磁浮列车的关键技术之一,但该技术目前仍不够成熟。对涡流制动技术进行研究,具有非常重要的理论意义和应用价值。[方法]建立了中低速磁浮列车线性涡流制动装置的模型,推导得到总涡流制动力F的计算式。为验证所设计涡流制动装置的减速效能,研制了涡流制动实物装置,并进行了台架试验。建立了电磁涡流制动力矩控制系统模型,分别基于开环控制算法、PID(比例-积分-微分)控制算法及模糊控制算法,得到这三种控制算法的中低速磁浮列车制动力特征曲线,进而对中低速磁浮列车的电磁涡流制动效能进行了深入分析。[结果及结论]对比仿真结果和试验实测结果,列车制动力的变化趋势几乎一致,由此可认为所推导的数学模型可信度较高。开环控制算法存在明显的超调,模糊控制算法较PID控制算法表现更佳。

基于粒子群优化算法的磁浮列车自抗扰悬浮控制器研究

为提高磁浮列车悬浮系统的抗干扰性和稳定性,本文提出基于粒子群优化算法(PSO)的自抗扰悬浮控制器。首先建立单电磁铁悬浮系统模型,然后基于该模型设计自抗扰控制器,最后引入粒子群优化算法对控制参数进行自适应寻优,得到适用于系统模型的自抗扰控制器。仿真和单悬浮架试验平台试验结果表明,系统受垂向加速度和悬浮气隙干扰时,相较于传统比例积分微分(PID)控制器,经粒子群优化算法自适应寻优的自抗扰控制器具有更好的抗干扰性和鲁棒性,可为磁浮列车悬浮系统控制算法的工程应用提供新思路。