Design of a class of extended dynamic linear controller via LMI approach

Abstract

In this paper, a class of dynamic linear controller is presented and formulated in terms of linear matrix inequalities (LMIs) for multiobjective control. The structure of this class of controller is based on a generalization of the types of proper controller and proportional‐integral‐derivative (PID) controller, and possesses tunable pole dynamics as well as measurement derivatives. Following discussions on the structural characteristics and limitations, a design algorithm with multiobjective performance is presented for this type of proposed controller. Then, the achieved performance levels as well as simulations of the frequency and time responses of the proposed controller in comparison with the proper type and state feedback controllers are demonstrated through the numerical construction of pole regions with constrained H ₈, H ₂, and mixed H ₂/H ₈ optimization for two design models regarding aircraft longitudinal control and satellite attitude control, respectively.     

Optimal PID controller parameters for first order and second order systems with time delay using a connectionist approach

This article focuses on developing a neural controller based on a proportional integral derivative (PID) law. The main objective is to show that using neural networks represents a better alternative compared with other conventional models that were used in the past to express the tuning parameters as a function of process parameters such as process gain (K _P ), process time constants (τ₁, τ₂, etc.,) and process time delay (θ). A Levenberg-Marquardt backward propagation algorithm is used to get the required PID parameters corresponding to different types of processes. In the present study, the PID parameters for the first order plus time delay (FOPTD) and the second order plus time delay (SOPTD) are obtained. It was observed that very high R ² values between the actual PID parameters and the parameters obtained from the NN were achieved. Furthermore, the performance of PID control systems with FOPTD and SOPTD processes are applied on a number of case studies and compared with the conventional Zeigler-Nichols (Z-N) method of tuning PID controllers. Using the proposed NN controller was found to be efficient and the current method could be of potential use in control systems with gain scheduling also where the controller parameters are tuned according to a continuous gain schedule variable that changes based on different levels of process parameters.     

Application of the preview compensation control method to large gap control in hybrid magnetic suspension

ABSTRACT

Large-gap magnetic suspension is a conceptual design for experiments which can be used to investigate technical issues associated with magnetic suspension and accurate suspended-load control for large gaps. The traditional linear control strategy has significant limits to its control area, usually around the chosen operating points. With increase in the suspension gap, the nonlinearity and time delay of a system will become more serious. Additionally, the interaction of an estimation scheme and corresponding controller has not been fully examined in the literature. This paper examines a developed compound control method, Smith forecast compensation control with proportional-integral-derivative control (PID control) , as a means of advancing the achievable performance of magnetic suspension. We designed and built a laboratory testbed to determine the feasibility of utilizing proposed methods in these types of applications. The analytical results are supported by the simulations and experiments, showing our research approach to be fairly successful at providing satisfactory performance for motion control under conditions involving a large air gap.     

多开关磁阻电机无轴传动系统同步控制方法

目的解决多开关磁阻电机同步控制中输出功率不平衡的问题,提高印刷业的生产效率和产品质量。方法在传统交叉耦合同步策略的基础上,提出一种基于神经元变结构PID控制的同步控制方法,该控制策略用一个神经元控制器实现变结构PID控制,同时用另一个神经元控制器实时调整变结构PID控制器的参数,从而保证2台开关磁阻电机的输出功率相同。结果通过仿真数据分析,其达到稳态的调节时间和动态响应时间比现有的同步控制小,且抗干扰能力也得到了提高。结论该策略可提高多电机同步控制系统的同步跟随性能和抗干扰性能,增强多电机无轴传动的同步协调控制能力。     

基于无速度传感器直接转矩控制自抗扰交流调速研究

在感应电机直接转矩控制(DYC)调速系统中,常规PID速度调节器在电机受到扰动的情况下,需要花费较长时间才能使电机恢复到稳态值.为此,将一种新型的自抗扰控制器(ADRC)引入感应电机直接转矩控制调速系统中,设计速度ADRc调节器代替PID调节器,基于模型参考自适应控制(MRAS)方法设计速度观测器.对比分析了PID与ADRC两种方案下无速度传感器直接转矩控制交流调速系统性能.仿真试验结果表明,采用ADRC后,系统动态响应更快,抗扰动能力更强,在电机参数摄动的情况下,电机运行速度与指令速度偏差更小.     

Development of Run-To-Run (R2R) controller for the multiple-input multiple-output (MIMO) system using fuzzy control theories

Run-to-Run (R2R) control has been extensively applied in semiconductor manufacturing. In particular, del Castillo, E. and Rajagopal, R., A multivariate double EWMA process adjustment scheme for drifting processes. IIE Trans., 2002, 34, 1055–1068, investigated double multivariate exponentially weighted moving average (MEWMA) controller for the multiple-input multiple-output (MIMO) system in an attempt to adjust and maintain the linear dynamic process outputs on target. Multivariate fuzzy control, inherently different from conventional MEWMA-based control, is another promising alternative that consists of fuzzy logic and set concept. Providing the fuzzy control can structure an appropriate membership function for the R2R MIMO system, thus it can be shown a practically useful control tool in comparison to MEWMA control. In this paper, fuzzy logic is utilized to design the multivariate fuzzy controller for the type of R2R applications based primarily on the min-max-gravity method advocated by Gupta, M.M., Kiszka, J.B. and Trojan, G.M., Multivariable structure of fuzzy control systems. IEEE Trans. Sys., Man Cybern., 1986, 16, 638–656. Under a variety of disturbance models, the proposed multivariate fuzzy controller can produce quite competitive control performance when compared to MEWMA control.     

六自由度运动平台控制系统的神经网络优化

阐述了六自由度运动平台的控制原理，并根据控制系统的特点，提出采用基于RBF和BP神经网络来改进常规PID控制器实现系统控制性能。在该控制系统结构中，提出了在RBF网络辨识Jacobian的基础上，将BP神经网络引入了平台控制系统中PID控制器的控制参数在线整定的算法，最后给出了在MATLAB下的具体仿真算法。     

改进粒子群算法的啤酒灌装机液位控制PID参数整定

目的 整定最优的PID控制参数,对啤酒灌装机中贮液罐液位进行控制,以保证PID控制器能满足啤酒生产中的控制要求。方法 结合Rosenbrock搜索法和个体扰动策略来改进粒子群算法,并利用改进算法整定PID参数,最后将整定好参数的PID控制器用于控制液位对象;基于Matlab进行仿真实验,利用粒子群算法与文中方法做比较。结果 通过Matlab仿真验证,改进了粒子群算法整定的PID参数,其跟踪特性的调节时间为16.18 s,超调量为10.20%,IAE性能指标约为6.09;粒子群算法整定结果表明,跟踪特性的调节时间为27.72 s,超调量为26.90%,IAE性能指标约为7.23。结论 与原始粒子群算法相比,文中算法整定的3个PID参数在控制液位对象时综合性能评价指标更好,且能使系统平稳过渡,超调较小,响应速度快,调节时间快,其控制器性能能满足啤酒灌装机的生产要求。     

卷筒料印刷装备收卷张力系统解耦控制研究

目的 为了保证卷筒料印刷装备收卷张力系统的性能,提出一种适用于收卷张力系统的自抗扰（ADRC）解耦控制器。方法 在收卷张力系统数学模型基础上,结合卷筒料收卷系统的工作原理,基于ADRC控制技术设计收卷张力系统的ADRC解耦控制器,并利用Simulink软件对所提出的控制策略进行仿真研究。结果 在相同的阶跃输入下,研究结果表明,PID控制器调整时间为2.4 s,而ADRC解耦控制器调整时间为0.7 s;在PID控制下,收卷基材张力出现超调和震荡,而在ADRC解耦控制下,基材张力无超调和震荡现象;采用PID控制器,收卷牵引跨度张力变化引起收卷跨度张力波动,而采用ADRC控制器则没有波动。结论 提出的卷筒料印刷装备收卷张力系统ADRC解耦控制器实现了高精度张力控制,具有比传统PID控制器更好的控制性能。     

基于双模糊PID的药品包装贴标张力控制系统设计

目的 为提高药品包装的贴标精度,设计一种基于双模糊PID控制器的贴标机张力控制系统。方法 简要论述药品包装生产线结构及其工艺流程。针对标签纸带收卷过程具有时变性、非线性和动态干扰等特点,设计一种双模糊PID张力控制器。利用副模糊控制器实现主模糊控制器的变量论域系数整定,而主模糊控制器可实现PID控制器参数整定。通过实验验证所述控制系统的有效性。结果 实验结果表明,与PID控制器相比,双模糊PID控制可使系统超调量减小50%,系统调节时间减小65%;贴标位置准确、标签贴附平整。结论 所述控制系统具有较好的抗干扰性能,贴标效果良好,具有一定使用价值。     

基于模糊设定值加权IMC-PID算法的纸张定量控制

目的 造纸机定量控制系统存在时滞性大、非线性和干扰多等困难,传统的PID控制动静态性能差,已无法满足越来越高的生产需求,为了减小纸张定量的偏差拟研究新的控制策略。方法 在传统内模控制和内模PID（IMC-PID）控制的基础上,结合模糊算法,设计模糊设定值加权IMC-PID算法控制系统。该控制算法通过在线整定内模PID控制器比例作用部分的设定值加权系数,改善控制系统性能指标,并将该控制算法应用到纸张定量中,与传统控制算法进行对比。结果 传统PID控制与内模PID控制相比较,基于模糊设定值加权IMC-PID算法具有良好的跟踪性和抗干扰能力等。结论 基于模糊设定值加权IMC-PID算法可有效控制造纸机定量控制系统,能够明显提高系统的控制精度等性能指标。     

模糊自适应PID控制在张力控制中的应用

针对凹版印刷机张力控制系统是一个非线性、强藕合、时变的复杂系统,用普通的PID难以达到理想的控制效果,设计出一种基于模糊控制原理的自适应PID控制器,根据偏差和偏差变化率来实时调整KP、KI、KD的参数.仿真结果表明,这种模糊自适应PID比常规PID控制器在张力控制中具有更好的控制性能.     

有约束复杂随动系统模型建立与控制研究

提出了一种有约束复杂随动系统--小碗摆球系统,并以小碗摆球系统为研究对象,针对有约束复杂随动系统的控制策略进行研究;利用拉格朗日动力学方法建立了小碗摆球系统的动力学模型。在讨论了系统能控和能观性的基础上分别采用鲁棒性双闭环PID控制和基于遗传算法的线性二次型最优控制进行了实际系统控制效果的实验对比,对比结果表明鲁棒性双闭环PID控制器具有更好的鲁棒性和瞬态特性,而遗传算法优化的线性二次型控制具有更好的动态特性。     

基于模糊自适应PID控制器的张力控制系统

针对常规PID控制在张力控制中,控制参数难以整定的问题,设计出一种基于模糊控制原理的自适应PID控制器,根据偏差和偏差变化率来实时调整Kp、Ki、Kd参数.仿真结果显示,这种模糊自适应PID控制器比常规PID控制器在张力控制中有更好的控制特性.     

LQG optimal controller synthesis with robust optimization in multivariable systems

Abstract

This paper presents an algorithm to synthesize a controller for treating the problem of robustness optimization in an LQG (linear‐quadratic‐Gaussian) control system. The controller not only maximizes the excess stability margin in perturbed system but also minimizes the cost functional J in LQG problems by specifying two frequency dependent weighting matrices Q(s) and R(s) in the cost functional.

Our approach is based on Wiener‐Hopf's technique (frequency domain approach), and two weighting matrices in cost functional are shaped by inverse LQG method. The feature of this paper is that the plant of the system has no stable, proper, square, and minimum phase constraints.     

基于扰动抑制的差分进化算法的纸浆浓度控制系统

目的为了解决传统单PID控制优化算法仅关注跟踪性能,无法满足在纸浆浓度控制系统等工业生产环节中控制品质和成品良率的需求。方法将PID控制系统离散化以计算在高斯扰动下的输出方差作为扰动抑制的依据,并结合ITAE指标通过差分进化算法优化PID性能。结果仿真表明,该整定方法可以通过权值选取优化的偏好,自由调节PID控制器的性能表现,对比基于Z-N法的PID控制和基于PSO算法优化的PID控制,基于扰动抑制差分进化算法的PID控制的ITAE指标为14.3495,输出方差为31.8530,均优于其他2种算法。结论基于扰动抑制的差分进化算法可以通过用户自定义权重来协调纸浆浓度的输出方差和跟踪性能,从更实际的角度整定纸浆浓度控制系统的PID控制器参数,使得控制系统的性能指标满足工业生产要求。     

基于模糊短反馈PID控制的粉末包装计量控制系统

目的粉末包装计量控制系统具有非线性等特点,传统的PID控制越来越无法满足工业产品包装的性能要求,为了提高包装机计量控制系统的速度、精度以及稳定性等,以实现快速精准的产品包装。方法在现有控制理论的基础上,结合模糊控制理论和生物神经内分泌腺体激素调节的原理,提出一种基于模糊短反馈PID控制的粉末包装计量控制系统。模糊控制的引入可以实现对传统PID控制器参数的在线调整;短反馈算法的引入可以使模糊PID控制更加精确、快速,并将该新型控制算法应用到粉末包装定量控制系统中与传统控制算法进行对比。结果通过Matlab中的Simulink工具箱搭建模糊短反馈PID控制的粉末包装计量控制系统仿真平台,并与传统的PID控制和模糊PID控制进行了比较可知,该系统具有响应速度快、抗干扰能力强等优良的性能。结论通过仿真验证可知,模糊短反馈PID控制的粉末包装计量控制系统具有稳定性好、响应快等良好的性能指标,同时具备一定的抗干扰能力。     

空调房间温度模糊分数阶PID控制器的设计

针对具有大时滞、大惯性和时变等动态特性的空调房间对象,综合模糊控制与分数阶PID控制理论,提出了模糊分数阶PID室温控制器的设计方法.首先,对于空调房间温度对象,进行数学建模.然后,运用模糊控制规则,获取相应的分数阶PID室温控制器的控制参数,从而构建出空调房间温度的模糊分数阶PID控制系统.并且,通过数值仿真对其进行验证.结果表明,该模糊分数阶PID室温控制器是可行的,与分数阶PID控制器相比,具有更好的控制性能.     

基于模糊内模-PID的包装机热封切刀温度控制

目的 包装机热封切刀温度控制系统存在非线性、大滞后性等特点,传统PID控制的效果也越来越无法满足工艺生产的要求,为了提高包装机热封切刀温度控制的速度和精度,进而提高封口的质量,以提高产品包装效率和品质。方法 在传统的PID控制的基础上,通过结合模糊控制和内模控制理论的先进控制算法,提出模糊内模-PID控制算法的包装机热封切刀温度控制系统。内模控制能够使PID控制器参数进行简化,同时模糊控制的引入能够实现控制器参数的在线调整,将该新型控制算法应用到包装机热封切刀温度控制系统中,并与传统控制进行对比。结果 通过Matlab仿真软件搭建模内模-PID控制的包装机热封切刀温度控制系统仿真平台,仿真结果表明,系统响应速度、精度、超调量、抗扰动能力等比传统控制系统性能更加优良。结论 通过仿真验证了模糊内模-PID控制在热封切刀温度控制系统上的有效性和可行性,能够在温度控制系统中表现出优良的性能指标。     

Development of a telepresence robot with adaptive shared controller

ABSTRACT

This study presents the design and control of a telepresence robot based on an omnidirectional mobile platform. A personal computer is used as a user interface for communication via internet to a laptop computer placed on the mobile platform. The laptop computer receives user’s commands to control the mobile robot. Collisions of robot with obstacle can still occur during remote controlling because of the limitation of a fixed camera on the robot and/or internet latency. We first use an artificial potential field to prevent these collisions, and then design an adaptive shared controller (ASC) to improve the performance. This ASC method modulates the weights of human control and assistance control online not only according to environmental factors, but also based on the user’s control performance. Meanwhile, we use the iterated closest point (ICP) algorithm to build a map for providing user functional reference. The experimental results show that ASC is efficient in both obstacle avoidance and user workload reduction.