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This paper presents a new design method of model predictive control (MPC) based on extended non-minimal state space models, in which the measured input and output variables, their past values together with the defined output errors are chosen as the state variables. It shows that this approach does not need the design of an observer to access the state information any more and by augmenting the process model and its objective function to include the changes of the system state variables, the control performances are superior to those of the controller that does not bear this feature. Furthermore, closed-loop transfer function representation of the model predictive control system facilitates the use of frequency response analysis methods for the nominal control performances of the system. 相似文献
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An approach to minimize tuning effort of nominal Model Predictive Control algorithms is proposed. The algorithm dynamically calculates output set points to accommodate user-defined output importance, which is more intuitive than selecting values for the MPC weighing matrices. Instead of tuning the weights on the outputs deviations from their set points, weights on the input values and input increments, which are the usual tuning parameters of MPC, the desired output control performance of the MPC can be specified by performance factors. The proposed method extends the existing methods that consider a reference trajectory for the output tracking to the case of zone control and input targets. The proposed method also assumes that, as in most commercial MPC packages, the controller has two layers: a static layer and an extended dynamic layer. The method is illustrated by three case studies, contemplating both SISO and MIMO systems. It is observed that: the output set point tracking performance can be changed without modifying the MPC tuning weights, the approach is capable of achieving similar performance to conventional MPC tuned by multiobjective optimization techniques from the literature, with a fraction of computer effort, and it can be integrated with Real Time Optimization algorithms to control complex systems, always respecting output constraints. 相似文献
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本文介绍了简化模型预测控制算法SM-PC,指出SMPC算法是作为克服内部模型控制(IMC)因式分解中求取过程传函逆阵费时等缺点而推出的一种简化算法。将本算法通过对一个多侧线精馏塔进行仿真,结果表明此算法具有良好的控制效果 相似文献
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In this paper, an improved approach of extended non-minimal state space (ENMSS) fractional order model predictive control (FMPC) is presented and tested on the temperature model of an industrial heating furnace. In the fractional order model predictive control algorithm, fractional order single-input single-output (SISO) system is discretized via fractional order Grünwald-Letnikov (GL) definition. The ENMSS fractional order model that contains the state variable and the fractional order output tracking error is formulated by choosing appropriate state variables. Meanwhile, the fractional order integral is introduced into the cost function and the GL definition is used to obtain the discrete form of the continuous cost function. Then the control signals are derived by minimizing the fractional order cost function. Lastly, the temperature process control of a heating furnace is illustrated to reflect the performance of the proposed FMPC method. Simulation results show the effectiveness of the proposed FMPC method. 相似文献
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This article considers pole assignment control of non-linear dynamic systems described by state-dependent parameter (SDP) models. The approach follows from earlier research into linear proportional-integral-plus methods but, in SDP system control, the control coefficients are updated at each sampling instant on the basis of the latest SDP relationships. Alternatively, algebraic solutions can be derived off-line to yield a practically useful control algorithm that is relatively straightforward to implement on a digital computer, requiring only the storage of delayed system variables, coupled with straightforward arithmetic expressions in the control software. Although the analysis is limited to the case when the open-loop system has no zeros, time delays are handled automatically. This article shows that the closed-loop system reduces to a linear transfer function with the specified (design) poles. Hence, assuming pole assignability at each sample, global stability of the non-linear system is guaranteed at the design stage. 相似文献
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本文提出一种基于动态矩阵控制(DMC)算法预测特性的新型PID控制方法.在考虑将来的输出期望偏差罚函数最小的前提下,由DMC计算出控制变量的值.继而构造基于DMC的预估器用以预测将来时刻的系统输出.根据将来时刻的多步预测偏差,PID控制器产生当前时刻的实际控制增量.文中也给出了基于DMC的预估器及PID控制器的参数整定方法.仿真结果表明,与常规的PID控制和DMC控制相比,所提方法具有良好的控制性能,扰动抑制尤其优良. 相似文献
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Most research into non-minimal state variable feedback control, in which the state vector is implemented directly from the measured input and output signals of the controlled process, has considered discrete-time systems represented using either the backward shift or delta operator. However, mechanistic models with physically meaningful parameters are often expressed in terms of differential equations, represented using the Laplace transform or s-operator, and this article is concerned with multivariable design for such models. The controllability conditions are developed and it is shown how the introduction of a diagonal polynomial matrix for filtering yields a control system that is immediately realisable in practice. Worked examples include optimal control with multi-objective optimisation and pole assignment design with analytical multivariable decoupling, with the latter illustrated by its application to a nonlinear wind turbine simulation. 相似文献
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针对线性多变量系统, 将前馈解耦控制与有限时间最优跟踪控制相结合, 提出一种新的最优解耦控制方法. 首先, 将关于状态的微分方程转化成关于输出的微分方程, 将系统内部矩阵和控制输入矩阵分别分解成对角矩阵和对角元为零的矩阵; 然后, 通过引入中间虚拟变量, 采用前馈和输出反馈的方法对系统进行解耦; 最后, 采用有限时间最优跟踪控制方法实现系统对任意参考输入的跟踪. 仿真结果表明了所提出方法的有效性和优越性. 相似文献
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针对传统控制方法难以解决自由漂浮空间机器人(free-floating space robot, FFSR)轨迹跟踪过程中的各类约束的问题,采用模型预测控制对自由漂浮空间机器人的轨迹跟踪问题进行了研究.在自由漂浮空间机器人拉格朗日动力学模型的基础上,建立了系统伪线性化的扩展状态空间模型;在给定系统的性能指标和各类约束的情况下,基于拉盖尔模型设计相应的离散模型预测控制器,并证明控制器的稳定性,控制器中引入任务空间滑模变量实现了对末端期望位置和期望速度的同时跟踪;以平面二杆自由漂浮空间机器人为例,对无约束末端轨迹跟踪和有约束末端轨迹跟踪两种情况进行对比仿真验证.仿真结果表明,该模型预测控制器不仅可以实现对末端期望轨迹的有效跟踪,还能满足各类约束. 相似文献
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针对无法从工业过程中获得准确状态空间模型的问题,提出一种基于子空间辨识的状态空间模型预测控制方法。利用子空间辨识方法得到的状态空间模型作为系统模型,给出约束条件下的预测控制算法。以CD播放器机械臂系统为例,通过状态空间模型预测控制方法实现对系统输出的跟踪控制,仿真结果表明,该方法控制效果良好。 相似文献
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Even though employed widely in industrial practice, the popular PID controller has weaknesses that limit its achievable performance, and an intrinsic structure that makes tuning not only more complex than necessary, but also less transparent with respect to the key attributes of the overall controller performance, namely: robustness, set-point tracking, and disturbance rejection. In this paper, we propose an alternative control scheme that combines the simplicity of the PID controller with the versatility of model predictive control (MPC) while avoiding the tuning problems associated with both. The tuning parameters of the proposed control scheme are related directly to the controller performance attributes; they are normalized to lie between 0 and 1; and they arise naturally from the formulation in a manner that makes it possible to tune the controller directly for each performance attribute independently. The result is a controller that can be designed and implemented much more directly and transparently, and one that outperforms the classical PID controller both in set-point tracking and disturbance rejection while using precisely the same process reaction curve information required to tune PID controllers. The design, implementation and performance of the controller are demonstrated via simulation on a nonlinear polymerization process. 相似文献
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研究控制项含有时滞的线性系统的预测控制问题.利用被控对象的预测输出向量和系统的控制向量,设计了一种降维状态预测观测器,并将该状态观测器用于时滞控制系统的最优状态反馈控制中.利用该状态预测观测器可将闭环系统的时滞项移至系统闭环结构之外,从而最优控制规律完全可以按无时滞系统进行设计.由性能指标计算公式表明,该预测控制器关于二次型性能指标是次优的. 相似文献
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关于状态反馈预测控制系统的极点配置 总被引:4,自引:2,他引:2
讨论按极点配置方法的设计问题,给出极点可任意配置的充分必要条件。基于状态空间模型,给出按极点配置方法设计时选取预测时域的方法。通过引入控制作用衰减系数及状态反馈加权系数,状态反馈预测控制系统的极点可任意配置。设计参数实时在线调整方便,增强了预测模型的适应范围,使预测控制系统具有较好的的控制性能和鲁棒性。 相似文献
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针对一类具有输出反馈耦合的离散非线性系统,将过程的非线性状态空间模型等效为线性时变状态空间模型;然后利用最小二乘法辨识系统参数,并通过在目标函数中引入系统状态的变化给出一种具有类似离散PI最优调节器结构的新型自适应预测函数控制器.由于引入了新的优化目标函数,该控制器控制效果与鲁棒性要优于仅考虑预测输出误差的传统预测函数控制器.仿真结果表明,该控制器优于经典离散PI最优调节器. 相似文献
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针对传统的模型预测控制器鲁棒性较差及模糊PID控制系统比较复杂的问题,提出了利用增广非最小状态空间模型与模型预测控制相结合的稳定平台预测控制。建立了稳定平台广义被控对象的数学模型,以增广形式的非最小状态空间模型为基础,结合滚动时域控制原则和线性二次型最优控制,通过对稳定平台离散模型的非最小状态空间形式进行增广变换,给出了基于Laguerre函数的状态反馈增益矩阵算法,设计了增广非最小状态模型下的预测控制器,实现了对导向钻井稳定平台控制系统的仿真研究。仿真结果表明稳定平台预测控制系统可以很好地满足钻井工程对控制精度和动态特性的要求,而且对有时变性的盘阀摩擦干扰力矩及模型参数摄动具有较强的鲁棒性。 相似文献
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通过适当调整状态反馈预测控制系统的设计参数—预测时域、控制作用衰减系数及状态反馈加权系数 ,使系统具有较好的控制性能和鲁棒性 ,在线调整设计参数方便灵活 ,实际工程应用范围增强 ,并给出了稳定塔蒸气压力控制的应用实例。 相似文献
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针对航空发动机高空环境模拟过渡态试验对高空舱进气环境压力模拟系统提出的强抗扰性、强鲁棒性等控制综合品质要求,设计了一种基于鲁棒模型预测控制(Robust Model Predictive Control,RMPC)的高空舱进气环境压力控制方法。RMPC采用滚动时域优化和扰动反馈补偿的方法,在预测控制框架内处理模型的不确定性。通过建立进气环境压力模拟系统设备特性模型,设计了基于RMPC的进气环境压力控制策略,搭建了仿真平台,与线性自抗扰控制(Linear Active Disturbance Rejection Control,LADRC)方法进行了对比分析。仿真结果表明,应用RMPC技术后,动态调节时间由7.68 s缩短至3.91 s,最大瞬时波动量由0.94%减小至0.25%,该技术能够大幅提高发动机高空环境模拟过渡态试验中进气环境压力模拟的动态响应速度、控制精度和抗扰能力。 相似文献