控制器参数对磁浮轴承系统控制特性的影响研究

在刚性非线性单自由度磁浮轴承转子系统动力学模型的基础上,考虑到PID控制策略的简便、易实现、实用、技术成熟等优点,采用M atlab对一实际磁浮轴承转子系统实现了PID控制仿真,得到了系统在某些参数域中的动态性能曲线。结果表明:控制器的参数对磁浮轴承转子系统控制性能有重要的影响,为更好实现磁浮轴承转子系统的稳定控制提供理论参考。     

磁浮轴承的控制和动态过程研究

建立了磁浮轴承的近似非最小相位传递函数模型，并基于此模型设计了保证系统稳定的闭环控制器。通过控制系统仿真对控制器参数进行了整定，分析了在不同扰动下转子的位移变化、电磁力和刚度的变化以及转子在高速时失控的原因，探讨了控制器参数与电磁轴承刚度及运转稳定性之间的变化关系。     

超高速数控磨床磁浮电主轴的研究

介绍了磁浮轴承的优点和发展现状，并通过现场磨削试验来检验磁浮轴承电主轴的磨削性能。磁浮轴承控制器是以浮点DSP芯片TMS320C32为核心构建的数字控制系统。针对轴承套圈内圆磨削时主轴转子受力的特点确定了合适的控制器参数，使电主轴静态稳定：悬浮并以60kr／min工作转速稳定运转，同步振幅小，轴承刚度高。现场磨削试验表明：磁悬浮电主轴的磨削精度基本满足要求，精磨效率接近工业应用水平。     

用于转子振动主动控制的数字式磁悬浮控制器的研究

交叉刚度是引起轴承－转子系统不稳定的主要因素之一［２］。以系统增稳为目的，本文提出了一种利用闭环磁悬浮振动控制器对转子施加主动交叉刚度力以削弱原系统交叉刚度，促使系统稳定的方法。笔者以ＩＮＴＥＬ８０９８十六位单片机为核心构成磁悬浮数字控制系统，软件设计以数字系统模拟化设计技术为前提，采用稳定性较好的双线性变换法实现复频域传递函数到离散域传递函数的转换。实验研究表明，该磁悬浮系统以非线性ＰＩＤ控制规律作为控制算法实现的磁悬浮轴承可使转子单端悬浮并具有较为良好的动态特性。     

数字控制的电磁轴承系统的研究

本文介绍了电磁轴承系统的数字控制器的组成及基本工作原理,建立了数字控制器的等效传递函数。对数控电磁轴承系统进行了起浮仿真及频域分析。在此基础上选取了控制器参数并进行了实验,实现了１６ｋｇ水平转子的稳定起浮和高速旋转,转速超过１２,０００ｒ／ｍｉｎ。     

基于四自由度整体控制模型的径向磁悬浮轴承预测控制

四自由度径向磁悬浮轴承系统控制复杂，且通常采取从单自由度出发设计控制器。提出了一种基于径向四自由度整体控制模型预测控制方法，由磁悬浮轴承的动力学方程得到四自由度径向轴承线性化模型，利用Simulink进行仿真并与PID控制效果进行比较。结果表明，模型预测控制的控制器设计简单，无需解耦，无论转子高速或者低速运行，均可控制系统平稳进入稳定状态，没有振荡和超调问题，比PID解耦下的控制效果更加接近实际系统。     

基于TMS320F28335DSP的磁悬浮系统数字控制器研究

以TMS320F28335和MAX7064SLC44-10为核心,设计了五自由度磁悬浮轴承柔性转子系统控制器硬件电路,采用C语言编制了基于CCS3.3开发环境的不完全微分PID控制程序。在该控制器的控制下,磁悬浮轴承柔性转子系统具有较强的鲁棒性和抗干扰能力,可以顺利越过前2阶弯曲临界转速。     

主动磁力轴承非线性动刚度特性研究

通过对主动磁力轴承转子系统非线性动刚度的研究,揭示了系统控制器参数、机械结构参数与动刚度之间的耦合关系,并结合PID控制规律,研究了磁力轴承非线性动刚度的频域特性.研究表明,系统在低频与高频段具有较高的支承刚度,而中频段刚度较低,刚度幅频特性呈"浴盆"状.在系统稳定区域内,改变控制器参数可以灵活地设计系统的动刚度.     

H∞控制理论在磁悬浮轴承系统中的应用研究

讨论了鲁棒H∞控制理论灵敏度和补灵敏度加权因子的选择方法，设计了磁悬浮轴承系统的H∞控制器；研制了基于PC机的磁悬浮轴承实时数控系统，用C语言设计了H∞控制器的软件。仿真结果表明，采用H∞控制，系统具有良好的动态性能、较强的鲁棒性和抑制转子振动的能力。对一个五自由度的磁悬浮轴承系统进行试验研究，结果表明，采用H∞控制器成功实现了五自由度磁悬浮轴承系统的稳定悬浮，在最高转速30000r／min时转子的振动峰峰值小于60μm。     

适应于飞轮储能系统的主动磁悬浮轴承专家控制方法研究

针对电磁力支撑的轴承转子因加工精度影响存在不平衡及定子线圈缠绕不均匀,导致相同PID控制参数不同转速下,支撑效果不一的问题,提出一种应用于主动磁悬浮轴承的分工况智能PID专家控制方法,使主动磁悬浮轴承控制系统具备一定抗干扰和抗积分饱和的能力。根据主动磁悬浮轴承的工作特点,将其转速分成若干区间,对每一个区间参数预整定,通过专家控制方法实现对控制器参数在线修正。以600Wh飞轮储能径向磁悬浮轴承为实验对象,提取的转子轴心轨迹表明:由于在控制器设计时考虑了转子不平衡和定子缠绕不均对系统的影响,系统具有较好的动态和静态特性的同时提高了系统抗干扰能力。     

Classical controller design techniques for fractional order case

This paper presents some classical controller design techniques for the fractional order case. New robust lag, lag-lead, PI controller design methods for control systems with a fractional order interval transfer function (FOITF) are proposed using classical design methods with the Bode envelopes of the FOITF. These controllers satisfy the robust performance specifications of the fractional order interval plant. In order to design a classical PID controller, an optimization technique based on fractional order reference model is used. PID controller parameters are obtained using the least squares optimization method. Different PID controller parameters that satisfy stability have been obtained for the same plant.     

基于PSO自整定PID控制器的柔性臂振动控制

针对压电柔性机械臂运行过程中的弹性振动问题,提出了基于粒子群优化算法（particle swarm optimization,简称PSO）自整定比例积分微分（proportional integral differential,简称PID）控制器参数的柔性臂振动抑制方法。采用标准粒子群优化算法,以时间乘绝对误差积（integrated time and absolute error,简称ITAE）准则为适应度函数,整定PID控制器的3个控制参数K-p,K-i和K-d,并采用Matlab Simulink平台建立双连压电柔性机械臂振动控制仿真模型,研制基于虚拟仪器技术的柔性臂振动控制试验系统。仿真与试验结果表明,采用常规PID控制算法和基于PSO自整定的PID控制算法均能有效地抑制柔性机械臂的弹性振动,但后者的振动抑制效果、鲁棒性与稳定性优于前者。     

An adaptive PID like controller using mix locally recurrent neural network for robotic manipulator with variable payload

Being complex, non-linear and coupled system, the robotic manipulator cannot be effectively controlled using classical proportional-integral-derivative (PID) controller. To enhance the effectiveness of the conventional PID controller for the nonlinear and uncertain systems, gains of the PID controller should be conservatively tuned and should adapt to the process parameter variations. In this work, a mix locally recurrent neural network (MLRNN) architecture is investigated to mimic a conventional PID controller which consists of at most three hidden nodes which act as proportional, integral and derivative node. The gains of the mix locally recurrent neural network based PID (MLRNNPID) controller scheme are initialized with a newly developed cuckoo search algorithm (CSA) based optimization method rather than assuming randomly. A sequential learning based least square algorithm is then investigated for the on-line adaptation of the gains of MLRNNPID controller. The performance of the proposed controller scheme is tested against the plant parameters uncertainties and external disturbances for both links of the two link robotic manipulator with variable payload (TL-RMWVP). The stability of the proposed controller is analyzed using Lyapunov stability criteria. A performance comparison is carried out among MLRNNPID controller, CSA optimized NNPID (OPTNNPID) controller and CSA optimized conventional PID (OPTPID) controller in order to establish the effectiveness of the MLRNNPID controller.     

Sliding mode control with PID sliding surface and experimental application to an electromechanical plant

In this study, a sliding mode control system with a proportional+integral+derivative (PID) sliding surface is adopted to control the speed of an electromechanical plant. A robust sliding mode controller is derived so that the actual trajectory tracks the desired trajectory despite uncertainty, nonlinear dynamics, and external disturbances. The proposed sliding mode controller is chosen to ensure the stability of overall dynamics during the reaching phase and sliding phase. The stability of the system is guaranteed in the sense of the Lyapunov stability theorem. The chattering problem is overcome using a hyperbolic function for the sliding surface. Experimental results that are compared with the results of conventional PID verify that the proposed sliding mode controller can achieve favorable tracking performance, and it is robust with regard to uncertainties and disturbances.     

超磁致伸缩致动器的广义预测-多模PID控制

为了克服超磁致伸缩致动器的磁滞现象对精密驱动定位精度的影响,在进行磁滞补偿的前提下,研究了自校正PID控制方法,提出了基于广义预测控制的广义预测-多模PID控制方法。介绍了广义预测控制的主要思想,并由此导出PID参数与被控对象待估参数的关系,实现了广义预测PID控制;针对起动阶段控制效果不平稳的问题,提出了多模PID控制模式转换条件;最后,根据PID参数变化情况,建立致动器的多模PID控制方法,实现广义预测PID与常规PID的在线控制模式转换与控制。实验结果表明,采用广义预测-多模PID控制器,虽然单次平均运算时间比广义最小方差-模糊PID控制器长7ms,但跟踪误差均方差减少了0.066μm;同时改善了起动平稳性。提出的控制方法能有效消除由扰动带来的影响,提高跟踪精度,改善起动平稳性,适用于对实时性、控制精度要求较高的精密定位领域。     

Stabilization and PID tuning algorithms for second-order unstable processes with time-delays

Open-loop unstable systems with time-delays are often encountered in process industry, which are often more difficult to control than stable processes. In this paper, the stabilization by PID controller of second-order unstable processes, which can be represented as second-order deadtime with an unstable pole (SODUP) and second-order deadtime with two unstable poles (SODTUP), is performed via the necessary and sufficient criteria of Routh-Hurwitz stability analysis. The stability analysis provides improved understanding on the existence of a stabilizing range of each PID parameter. Three simple PID tuning algorithms are proposed to provide desired closed-loop performance-robustness within the stable regions of controller parameters obtained via the stability analysis. The proposed PID controllers show improved performance over those derived via some existing methods.     

Design PID controllers for desired time-domain or frequency-domain response

Practical requirements on the design of control systems, especially process control systems, are usually specified in terms of time-domain response, such as overshoot and rise time, or frequency-domain response, such as resonance peak and stability margin. Although numerous methods have been developed for the design of the proportional-integral-derivative (PID) controller, little work has been done in relation to the quantitative time-domain and frequency-domain responses. In this paper, we study the following problem: Given a nominal stable process with time delay, we design a suboptimal PID controller to achieve the required time-domain response or frequency-domain response for the nominal system or the uncertain system. An H(infinity) PID controller is developed based on optimal control theory and the parameters are derived analytically. Its properties are investigated and compared with that of two developed suboptimal controllers: an H2 PID controller and a Maclaurin PID controller. It is shown that all three controllers can provide the quantitative time-domain and frequency-domain responses.     

电动助力转向系统随动特性仿真

电动助力转向系统（Electric Power Steering,EPS）必须随时根据驾驶员的操作,提供渐进随动的转向助力动作,所以系统必须有很高的跟踪性和很好的稳定性．在对EPS的工作原理和力学模型分析的基础上,建立EPS系统仿真模型,设计出一种模糊自适应PID（Proportion—Integral—Derivative）控制器,有效地改善了传统PID控制器的不足．通过仿真表明,这种模糊自适应PID控制器与传统PID控制器相比,具有更好的跟踪性和稳定性．     

基于时域的分数阶PID预测函数励磁控制器

为了提高电力系统的稳定性,将分数阶PID算法与预测函数算法相结合,提出了一种新型的基于时域的分数阶PID预测函数励磁控制器的设计方法.该算法不仅具有分数阶PID静态误差小、上升速度快以及预测函数算法超调小、调节时间短的优点,还克服了分数阶PID调节时间长和预测函数算法静态误差大的缺点,同时还比预测函数算法多出了5个可调参数,设计更加灵活.研究结果表明该算法不仅能有效地解决机端电压偏移问题,还能有效地抑制电网低频振荡,为电力系统稳定性控制提供了一种新型有效的方法.     

扫描隧道显微镜微位移工作台的神经网络PID控制方法研究

提出了一种基于神经网络理论的微位移工作台控制方案。该工作台以压电陶瓷作为微位移驱动元件,对伺服电机大位移进行位移补偿。分析了压电陶瓷微位移驱动器的原理,建立了工作台的数学模型。神经网络PID控制器对工作台进行闭环控制,利用BP网络的自学习和自适应能力,实时调整网络加权值,改变PID控制器的控制系数,减小工作台的位移误差。采用专用的压电陶瓷驱动电源对工作台的位移进行了实验,相对于常规PID控制器,微位移为11.41 μm时的响应时间从1.5 s缩短到1 s,稳态位移误差从3.13％减小到1.05％,工作台的稳定性和定位精度得以提高,改善了扫描隧道显微镜的工作性能。