THE PRINCIPLE OF ROBUSTNESS IN GENERALIZED PREDICTIVE CONTROL

This paper deeply analyzes the closed-loop nature ofGPCin the fram ework ofinter- nalm odelcontrol(IMC) theory. A new sort ofrelation lies in the feedback structure so that robustreason can be satisfactorily explained. The resultissignificantbecause the previous con- clusions are only applied to open-loop stable plant(orm odel).

Neuro-fuzzy generalized predictive control of boiler steam temperature

Power plants are nonlinear and uncertain complex systems. Reliable control of superheated steam temperature is necessary to ensure high efficiency and high load-following capability in the operation of modem power plant. A nonlinear generalized predictive controller based on neuro-fuzzy network （NFGPC） is proposed in this paper. The proposed nonlinear controller is applied to control the superheated steam temperature of a 200MW power plant. From the experiments on the plant and the simulation of the plant, much better performance than the traditional controller is obtained,

A Long-Range Generalized Predictive Control Algorithm for a DFIG Based Wind Energy System

This paper presents a new Long-range generalized predictive controller in the synchronous reference frame for a wind energy system doubly-fed induction generator based. This controller uses the state space equations that consider the rotor current and voltage as state and control variables, to execute the predictive control action. Therefore, the model of the plant must be transformed into two discrete transference functions, by means of an auto-regressive moving average model, in order to attain a discrete and decoupled controller, which makes it possible to treat it as two independent single-input single-output systems instead of a magnetic coupled multiple-input multiple-output system. For achieving that, a direct power control strategy is used, based on the past and future rotor currents and voltages estimation. The algorithm evaluates the rotor current predictors for a defined prediction horizon and computes the new rotor voltages that must be injected to controlling the stator active and reactive powers. To evaluate the controller performance, some simulations were made using Matlab/Simulink. Experimental tests were carried out with a small-scale prototype assuming normal operating conditions with constant and variable wind speed profiles. Finally, some conclusions respect to the dynamic performance of this new controller are summarized.

Adaptive Cascade Generalized Predictive Control

Cascade control is one of the most popular structures for process control as it is a special architecture for dealing with disturbances. However, the drawbacks of cascade control are obvious that primary controller and secondary controller should be tuned together, which influences each other. In this paper, a new Adaptive Cascade Generalized Predictive Controller (ACGPC) is introduced. ACGPC is a method issued from GPC and the inner and outer controllers of a cascade system are replaced by one cascade generalized predictive controller, where both loops model are updated by Recursive Least Squares method. Compared with existing methods, the new method is simpler and yet more effective. It can be directly integrated into commercially available industrial auto-tuning systems. Some examples are given to illustrate the effectiveness and robustness of the proposed method.

ON THE ROBUSTNESS OF A GENERALIZED PREDICTIVE CONTROLLER

In this paper, we present a quantitative analysis of the robustness of a generalized predictive controller. The result of stability analysis shows that, under a specific bounded modelling error, the closed-loop system is BIBO stable in the presence of unmodelled dynamics.

Proportion integral-type active disturbance rejection generalized predictive control for distillation process based on grey wolf optimization parameter tuning

The high-purity distillation column system is strongly nonlinear and coupled,which makes it difficult to control.Active disturbance rejection control(ADRC)has been widely used in distillation systems,but it has limitations in controlling distillation systems with large time delays since ADRC employs ESO and feedback control law to estimate the total disturbance of the system without considering the large time delays.This paper designs a proportion integral-type active disturbance rejection generalized predictive control(PI-ADRGPC)algorithm to control the distillation column system with large time delay.It replaces the PD controller in ADRC with a proportion integral-type generalized predictive control(PI-GPC),thereby improving the performance of control systems with large time delays.Since the proposed controller has many parameters and is difficult to tune,this paper proposes to use the grey wolf optimization(GWO)to tune these parameters,whose structure can also be used by other intelligent optimization algorithms.The performance of GWO tuned PI-ADRGPC is compared with the control performance of GWO tuned ADRC method,multi-verse optimizer(MVO)tuned PI-ADRGPC and MVO tuned ADRC.The simulation results show that the proposed strategy can track reference well and has a good disturbance rejection performance.

Application of generalized predictive control in networked control system

A new framework for networked control system based on Generalized Predictive Control (GPC) is proposed in this paper. Clock-driven sensors, event-driven controller, and clock-driven actuators are required in this framework. A queuing strategy is proposed to overcome the network induced delay. Without redesigning, the proposed framework enables the existing GPC controller to be used in a network environment. It also does not require clock synchronization and is only slightly affected by bad network condition such as package loss. Various experiments are designed over the real network to test the proposed approach, which verify that the proposed approach can stabilize the Networked Control System (NCS) and is robust.

Improved Generalized Predictive Control Algorithm with Offline and Online Identification and Its Application to Fixed Bed Reactor

An improved generalized predictive control algorithm is presented in this paper by incorporating offline identification into onlie identification.Unlike the existing generalized predictive control algorithms.the proposed approach divides parameters of a predictive model into the time invariant and time-varying ones,which are treated respectively by offline and onlie identification algorithms.Therefore,both the reliability and accuracy of the predictive model are improved,Two simulation examples of control of a fixed bed reactor show that this new algorithm is not only reliable and stable in the case of uncertainties and abnormal distrubances,but also adaptable to slow time varying processes.

Generalized Predictive Control with Online Least Squares Support Vector Machines

这份报纸基于能有效地处理非线性的系统的联机最少的广场支持向量机器(LS-SVM ) 建议一个实际概括预兆的控制(GPC ) 算法。在每个采样时期，算法递归地由增加新数据对并且在实时性质上从考虑删除最不重要的修改模型。删除的数据对被 lagrange 的绝对值从最后一个采样时期更多样地决定。当增加新数据对并且删除存在的时，纸给模型参数的递归的算法分别地，一个大矩阵的倒置被避免，存储器能被算法完全控制。非线性的 LS-SVM 模型在每个采样时期在 GPC 算法被使用。抵销过程的 pH 上的概括预兆的控制的实验显示出建议算法的有效性和实物。

Weighted Adaptive Generalized Predictive Control for Carding Autoleveler

In textile industry, carding process has decisive influence on produced yarn quality. From the system theoretic point of view, it is marked by stochastic disturbance, long delays, and parameter variation. So, a carding process is difficult to control with traditional control algorithms (such as PID). In this paper, a weighted adaptive generalized predictive control (GPC) law was developed to control such a process. The experimental results show that GPC autoleveller controller could greatly reduce the sliver’s standard deviation and reject disturbance.

ADAPTIVE GENERALIZED PREDICTIVE CONTROL OFSWITCHED SYSTEMS

The problem of adaptive generalized predictive control which consists of output prediction errors for a class of switched systems is studied.The switching law is determined by the output predictive errors of a finite number of subsystems.For the single subsystem and multiple subsystems cases,it is proved that the given direct algorithm of generalized predictive control guarantees the global convergence of the system.This algorithm overcomes the inherent drawbacks of the slow convergence and large transient errors for the conventional adaptive control.

Global Convergence of Adaptive Generalized Predictive Controller Based on Least Squares Algorithm

Some papers on stochastic adaptive control schemes have established convergence algorithm using a least-squares parameters. With the popular application of GPC, global convergence has become a key problem in automatic control theory. However, now global convergence of GPC has not been established for algorithms in computing a least squares iteration. A generalized model of adaptive generalized predictive control is presented. The global convergebce is also given on the basis of estimating the parameters of GPC by least squares algorithm.

SIMULATION STUDY OF GENERALIZED PREDICTIVE CONTROL FOR TURBINE POWER

A GPC (generalized predictive control) law is developed to control the powerof a turbine, after transforming the nonlinear mathematical model of the power regulation systeminto a CARIMA(controlled auto-regressive integrated moving average) form. The effect of the newcontrol law is compared with a traditional PID (proportional, integral and differential) control lawby numerical simulation. The simulation results verify the effectiveness, the correctness and theadvantage of the new control scheme.

Parameter Self - Learning of Generalized Predictive Control Using BP Neural Network

This paper describes the self—adjustment of some tuning-knobs of the generalized predictive controller(GPC).A three feedforward neural network was utilized to on line learn two key tuning-knobs of GPC,and BP algorithm was used for the training of the linking-weights of the neural network.Hence it gets rid of the difficulty of choosing these tuning-knobs manually and provides easier condition for the wide applications of GPC on industrial plants.Simulation results illustrated the effectiveness of the method.

基于改进BSO算法的VAV空调系统GPC参数整定

针对变风量(variable air volume,VAV)空调系统具有大滞后、强耦合等控制难点,提出了一种基于改进天牛群优化(beetle swarm optimization,BSO)算法的VAV空调系统广义预测控制(generalized predictive control,GPC)参数整定方法。针对标准GPC整定算法只调节控制加权系数λ导致控制性能不佳的问题,首先,提出一种改进BSO算法,通过动态化选取权重参数与学习因子获得较佳的寻优性能。其次,提出一种基于改进BSO算法的新型GPC参数整定方法,可同时整定控制器的控制加权系数λ、控制时域Nu、预测时域Np及柔化系数α。最后,结合实际VAV空调系统,开展仿真与半实物实验。结果表明,采用改进BSO算法调优后GPC的控制效果得到显著提升,调节时间仅为7 s,超调量仅为0.28%。

Robust Continuous-time Generalized Predictive Control for Large Time-delay System

A simple delay-predictive continuous-time generalized predictive controller with filter (F-SDCGPC) is proposed. By using modified predictive output signal and cost function, the delay compensator is incorporated in the control law with observer structure, and a filter is added for enhancing robustness. The design of filter does not affect the nominal set-point response, and it is more flexible than the design of observer polynomial. The analysis and simulation results show that the F-SDCGPC has better robustness than the observer structure without filter when large time-delay error is considered.

ADRC-GPC算法在旋转倒立摆系统中的应用

自抗扰广义预测控制(ADRC-GPC)是一种由广义预测控制技术和自抗扰控制技术有机结合的新型控制算法。该算法首先利用扩张状态观测器(ESO)估计出系统的总扰动;其次,引入虚拟控制量以抵消该总扰动作用,使原被控对象系统转化为积分器串联型系统;最后,利用GPC对新系统进行收敛控制。ADRC-GPC不仅可以有效避免传统GPC的在线计算量过大问题,还无须使用状态量的高阶信息,相比传统ADRC大大降低了调参难度。针对一级旋转倒立摆稳定控制问题中的强耦合、非线性等难点,设计了双通道ADRC-GPC融合控制器。仿真实验结果表明:ADRC-GPC控制器能够使一级旋转倒立摆系统达到控制目的,其对多变量非线性不稳定系统具有良好的控制性能。

基于多模型γ增量型阶梯式GPC的SCR脱硝系统优化控制研究

提出了一种以入口NO_(x)质量浓度预测值作为前馈的多模型γ增量型阶梯式广义预测串级控制策略。首先,设计3个典型工况下的γ-SGPC-PID串级控制器,然后通过模糊增益调度构建全局控制器,最后将基于VMD-ARIMA的入口NO_(x)质量浓度预测值作为前馈,构建了前馈-反馈SCR脱硝控制系统。结果表明:该前馈-反馈控制系统可以对氨气质量流量进行准确调节,降低出口NO_(x)质量浓度的波动变化,提高了变工况下SCR脱硝系统的控制品质。

基于PSO的GPC-PID的细纱机锭速控制算法

针对细纱机在卷绕过程中由于纱线张力波动较大而导致的断头问题,提出了粒子群优化(particle swarm optimization,PSO)算法优化控制GPC-PID的锭子转速。首先,引入广义预测控制PID(GPC-PID)算法来控制锭子转速,并实时对PID进行参数整定,从而实时控制细纱机锭速。然后,引入PSO算法来提高GPC-PID的预测精度。最后,通过仿真实验,将常规的GPC-PID控制与PSO算法优化的GPC-PID控制进行比较。结果表明,锭子无刷直流电机在经PSO算法优化后的GPC-PID算法控制下,系统的快速性和稳定性都有一定提高,锭子的转速和转矩得到有效控制,纱线张力波动较小,降低了细纱卷绕过程中的断头率,证明了粒子群优化GPC-PID控制算法的优越性。