Dynamic matrix predictive control for a hydraulic looper system in hot strip mills

Controlling the looper height and strip tension is important in hot strip mills because these variables affect both the strip quality and strip threading. Many researchers have proposed and applied a variety of control schemes for this problem, but the increasingly strict market demand for strip quality requires further improvements. This work describes a dynamic matrix predictive control(DMC) strategy that realizes the optimal control of a hydraulic looper multivariable system. Simulation experiments for a traditional controller and the proposed DMC controller were conducted using MATLAB/Simulink software. The simulation results show that both controllers acquire good control effects with model matching. However, when the model is mismatched, the traditional controller produces an overshoot of 32.4% and a rising time of up to 2120.2 ms, which is unacceptable in a hydraulic looper system. The DMC controller restricts the overshoot to less than 0.08%, and the rising time is less than 48.6 ms in all cases.

Vector control of permanent magnet synchronous motor based on dynamic matrix control

Aiming at the control problem of strongly nonlinear and coupled permanent magnet synchronous motor(PMSM)oil rig,this paper presents a predictive control method based on dynamic matrix model.In this method,the dynamic matrix algorithm using multistep prediction technique is applied to the speed loop control of the motor vector control.And its control effect is compared with the traditional proportional integral(PI)control of the motor.By comparing the initial dynamic response and the steady-state recovery under load interference of the two methods,it is shown that the dynamic response and the robustness of the motor controlled by the new method is better than that controlled by conventional PI method.And the feasibility of new control in the application of PMSM oil rig is verified.

A practical predictive control algorithm for integral processes and a case study in boiler level system

The Dynamic Matrix Control （DMC） algorithm tor integral processes is investigated in this paper. The reason why the original DMC algorithm cannot be applied to these processes is analyzed. The shifting matrix is transformed into another form and the corresponding theorem is proved, then its applicable range is extended. Compared with other algorithms on the integral processes, this algorithm is more practical and simple to implement. Simulation results also prove its validity. Applying this algorithm, we succeed in the control of the boiler level system in power units.

Application of Model Predictive Control Based on Kalman Filter in Solar Collector Field of Solar Thermal Power Generation

There are two prominent features in the process of temperature control in solar collector field.Firstly,the dynamic model of solar collector field is nonlinear and complex,which needs to be simplified.Secondly,there are a lot of random and uncontrollable,measurable and unmeasurable disturbances in solar collector field.This paper uses Taylor formula and difference approximation method to design a dynamic matrix predictive control(DMC)by linearizing and discretizing the dynamic model of the solar collector field.In addition,the purpose of controlling the stability of the outlet solar field salt temperature is achieved by adjusting the mass flow of molten salt.In order to further improve the ability of the system to suppress unmeasured disturbances,a steady-state Kalman filter is designed to estimate state variables,so that the system has better stability and robustness.The simulation verification results show that the DMC control system based on Kamlan filtering has better control effect than the traditional DMC control system.In the case of large fluctuations in solar radiation intensity and consideration of undetectable interference,the overshoot of the system is reduced by 4%and the rise time remains unchanged.

基于Matlab/Simulink的三相动态负荷对实际电网动态仿真的应用

负荷是电力系统的重要组成部分之一,在仿真时选择或建立合适的负荷模型对电力系统稳定分析有很重要的影响。总结了在Matlab/Simulink的仿真环境中,其电力系统模块库中特有的三相动态负荷元件的三种工作模式,提出了两种当此元件处于“外部功率控制”工作状态实现负荷功率由外部控制的有效方法。并在某地区电网的基础上进行动态仿真,仿真结果表明这两种由外部控制三相动态负荷功率的方法可以实现在电力系统动态仿真中,对于电网模型搭建时在动态负荷元件的选择与运用以及电力系统稳定性分析时域仿真有一定程度的有参考价值。

基于Matlab/Simulink的沥青洒布电驱控制系统仿真研究

针对沥青喷洒系统控制精度高,动态性能好等要求,笔者提出了一种基于矢量控制的沥青泵电机驱动方案,通过Matlab/Simulink对整个电驱系统的模型进行搭建和动态仿真,仿真结果表明沥青洒布电驱控制系统动态响应快,抗负载扰动能力强,满足沥青洒布对控制洒布精度的设计要求。

Implementation of Dynamic Matrix Control on Field Programmable Gate Array

High performance computer is often required by model predictive control(MPC) systems due to the heavy online computation burden.To extend MPC to more application cases with low-cost computation facilities, the implementation of MPC controller on field programmable gate array(FPGA) system is studied.For the dynamic matrix control(DMC) algorithm,the main design idea and the implemental strategy of DMC controller are introduced based on a FPGA’s embedded system.The performance tests show that both the computation efficiency and the accuracy of the proposed controller can be satisfied due to the parallel computing capability of FPGA.

Finite Set-Model Predictive Current Control of Three-Phase Voltage Source Inverter for RES （Renewable Energy Systems） Applications

This paper focuses on a combination of three-phase VSI （voltage source inverter） with a predictive current control to provide an optimized system for three-phase inverters that control the load current. A FS-MPC （finite set-model predictive control） strategy for a three-phase VSI for RES （renewable energy systems） applications is implemented. The renewable energy systems model is used in this paper to investigate the system performance when power is supplied to resistive-inductive load. With three different cases, the evaluation of the system is done. Firstly, the robustness of control strategy under variable DC-Link is done in terms of the THD （total harmonic distortion）. Secondly, with one prediction step, the system performance is tested using different sampling time, and lastly, the dynamic response of the system with step change in the amplitude of the reference is investigated. The simulations and result analyses are carried out using Matlab/Simulink to test the effectiveness and robustness of FS-MPC for two-level VSI with AC filter for resistive-inductive load supplied by a renewable energy system.

Adaptive Predictive Inverse Control of Offshore Jacket Platform Based on Rough Neural Network

The offshore jacket platform is a complex and time-varying nonlinear system, which can be excited of harmful vibration by external loads. It is difficult to obtain an ideal control performance for passive control methods or traditional active control methods based on accurate mathematic model. In this paper, an adaptive inverse control method is proposed on the basis of novel rough neural networks （RNN） to control the harmful vibration of the offshore jacket platform, and the offshore jacket platform model is established by dynamic stiffness matrix （DSM） method. Benefited from the nonlinear processing ability of the neural networks and data interpretation ability of the rough set theory, RNN is utilized to identify the predictive inverse model of the offshore jacket platform system. Then the identified model is used as the adaptive predictive inverse controller to control the harmful vibration caused by wave and wind loads, and to deal with the delay problem caused by signal transmission in the control process. The numerical results show that the constructed novel RNN has advantages such as clear structure, fast training speed and strong error-tolerance ability, and the proposed method based on RNN can effectively control the harmful vibration of the offshore jacket platform.

MATLAB和Simulink环境下控制系统的动态仿真

文章着重阐述了在MATLAB和Simulink环境下对实际控制对象的动态仿真的过程和意义,同时对两种仿真方法进行了比较。

二次开发ForceControl嵌入带预测误差校正的动态矩阵控制算法

介绍了ForceControl组态软件的特点和功能。根据ForceControl的特点,提出了以ActiveX控件形式嵌入先进控制算法,对组态软件进行二次开发的方法。提出了一种带预测误差校正的动态矩阵控制算法,并制作成ActiveX控件嵌入到ForceControl中。

AGC环路设计的Matlab-Simulink模型建模及验证

基于Matlab-Simulink构建一个完整的自动增益控制环路(AGC)模型,并对模型进行了验证。该模型可从时间和功率幅度两个方面分析AGC控制过程,能够很好地显示和预测环路特性,从而可便捷地评估AGC环路是否满足系统的需求。在该模型的辅助下,以可变增益放大器、检波器、数/模转换器、模/数转换器与现场可编程门阵列为核心器件,实现了一种输入动态范围为-72～-12 dBm,输出动态范围为-19.7～-19.2 dBm际测试输出功率误差在1.3 dB以内,控制时间过程吻合,表明AGC环路的仿真和实测情况基本一致。

基于MATLAB/Simulink的常导高速磁浮列车垂向动力学建模与仿真

为了对常导高速磁浮列车系统特性进行更深入的了解,建立悬浮系统垂向动力学数学模型,并基于MATLAB/Simulink多体工具箱,对悬浮系统垂向动力学特性进行仿真研究。在额定负载条件下,系统起浮工况下的最大电流为80 A,当悬浮气隙调整为指令气隙12 mm时,稳态电流为27.5 A,与实际悬浮系统相符。此外,模型实现了变负载、气隙脉冲扰动、气隙指令调整等工况的模拟。模型将悬浮系统斩波电路、控制系统及动力学系统进行了统一,实现了系统电气特性与动力学特性的同步观测,改进了对系统单元进行分立仿真的传统方法。

基于RBF神经网络滑模控制的卷纸纠偏系统

设计了采用RBF神经网络控制的伺服纠偏控制系统,通过建立其动力学模型,运用MATLAB/Simulink仿真软件仿真,并进行实验验证,分析系统动态性能,得到响应曲线。结果表明,在拉纸速度65 mm/s下,跑偏量从1.5 mm降低到0.55 mm,该伺服系统位移和速度跟踪误差均较小。

基于Matlab的双足机器人动力学仿真及仿生控制平台

针对仿生控制的特点,构建了一种Matlab环境下的双足机器人动力学仿真及仿生控制平台。为了充分利用关节自身的被动特性,描述了由非外界约束引起的自由度变化,以及双足机器人在运动相态间的合理切换。同时,考虑到碰撞是机器人运动的固有特性,建立了包括碰撞在内的混合动力学模型,最终实现控制器与机器人、环境的耦合。在此平台上,对设计的仿生控制算法进行了仿真:借助机器人自身运动状态和环境交互信息,协调各个关节的动作时序,实现了低能耗的稳定行走。结果表明,该平台为双足机器人仿生控制及其运动特性分析提供了有效的仿真手段。

某水下打桩锤主控阀缓冲装置建模与仿真

为研究某水下打桩锤缓冲装置的结构对主控阀缓冲性能的影响,介绍缓冲装置的结构组成和缓冲原理,考虑液压油泄漏导致主控阀腔内压力和温度的变化,结合热力学和流体动力学理论建立缓冲装置的动态数学模型,基于MATLAB/Simulink软件搭建仿真模型并进行仿真分析,研究液压系统回油背压、缓冲腔直径、泄漏缝隙高度和长度等参数对缓冲性能的影响规律。结果表明:打桩锤主控阀缓冲装置的泄漏缝隙高度、泄漏缝隙长度和缓冲腔直径对缓冲性能的影响显著,液压系统的回油背压影响相对较小。研究结果为主控阀缓冲装置的设计和结构参数的优化提供理论依据。

基于SIMULINK/TargetLink拖拉机PTO软接合控制策略

以大功率轮式拖拉机动力输出(PTO)为研究对象,利用Matlab/SIMULINK软件建立了PTO动力学模型,用Target Link软件建立PTO软接合控制策略模型,然后将两者联合起来形成闭环系统,通过仿真分析,PTO带动不同负载时的接合过程时间能够控制在一定时间内。

基于Simulink的抽油机阀控液压缸的特性研究

在一种液压式抽油机上设计的比例阀控液压缸,用来控制抽油杆的速度,达到最佳速度曲线。以此为基础建立比例阀控液压缸的数学模型,利用MATLAB/Simulink对其动态特性、稳态特性进行研究,结果表明该比例阀控液压缸满足要求,对后续抽油机的研究提供了参考。

基于局部模型网络的主汽温阶梯式动态矩阵控制

火电厂主汽温系统的大惯性、时变性和多扰动等特点导致采用传统串级PID控制难以取得令人满意的控制效果。为了克服传统控制方案的缺陷,提出了一种基于局部模型网络的多模型阶梯式动态矩阵控制算法。首先,通过引入阶梯式策略有效解决了原始动态矩阵控制算法固有的矩阵求逆问题;其次,通过引入扰动前馈补偿,提高了主汽温系统的抗扰动能力;最后,针对不同工况下动态特性大幅度变化的主汽温对象,设计了基于局部模型网络的多模型阶梯式动态矩阵控制器。仿真结果表明,相比于传统控制算法,所提算法明显提升了主汽温系统的全局设定值跟踪性能、抗扰动性能和鲁棒性能,可以满足火电机组主汽温的控制要求。

A New Sliding Function for Discrete Predictive Sliding Mode Control of Time Delay Systems

The control of time delay systems is still an open area for research. This paper proposes an enhanced model predictive discrete-time sliding mode control with a new sliding function for a linear system with state delay. Firstly, a new sliding function including a present value and a past value of the state, called dynamic surface, is designed by means of linear matrix inequalities （LMIs）. Then, using this dynamic function and the rolling optimization method in the predictive control strategy, a discrete predictive sliding mode controller is synthesized. This new strategy is proposed to eliminate the undesirable effect of the delay term in the closed loop system. Also, the designed control strategy is more robust, and has a chattering reduction property and a faster convergence of the system s state. Finally, a numerical example is given to illustrate the effectiveness of the proposed control.