基于嵌入式B/S模式的机电产品远程监控系统

针对机电产品远程监控中基于图像与视频的信息控制能力不足的问题,在以PLC为控制器的控制系统基础上增加了ARM核心控制器,设计并实现了一种低成本的嵌入式B/S模式的机电产品远程实时监控系统方案。该系统利用Video4linux控制USB摄像头获取机电产品工作时图像数据,并采用PNG算法实现图像压缩,通过RS232接口完成ARM与PLC间的通信,以获取机电产品实时工作参数和实现控制指令的传递。该系统通过嵌入式Boa服务器,采用B/S模式实现,并通过CGI技术实现图像和数据的远程实时动态传输。研究结果表明:"ARM+PLC+Web"交互这一组合的嵌入式系统方案,可为当前机电产品远程监控存在无法满足图像与视频中信息控制能力不足的问题提供了一个很好的解决平台。     

基于基金会现场总线高速以太网的软PLC设备的研制

基金会现场总线（FF）对离散信号的处理能力不强，需要在其上集成PLC以弥补其不足。为此，研制了基于基金会现场总线高速以太网（FF HSE）的软PLC设备。阐明了该设备的系统组成、工作原理、开发系统和目标系统的设计与实现方法。提出了一种新颖的设计方案：在软PLC目标系统中采用2个嵌入式控制器分别实现系统的通信与控制功能。用于通信功能的嵌入式控制器把软PLC的分散控制功能集成到了基金会现场总线上。实验结果表明，设备对高速离散信号的处理能力强，能够无缝地集成于FFHSE上，有效地增强了FF现场总线控制系统对离散信号的处理能力。     

带钢冷轧闭环反馈控制最优化算法程序开发

基于多变量最优化控制的带钢闭环反馈控制模型能够充分利用弯辊和轧辊倾斜等平直度控制机构对板形偏差进行控制。闭环反馈控制的目的是使带钢实测板形与目标板形一致,闭环反馈最优化算法程序能充分利用输入信息,全面考虑多个执行机构对板形的作用,避免各控制之间的相互影响,它是该模型准确计算板形调节量的关键。为了实现自主建立带钢冷轧生产线,对某厂1 700 mm四机架四辊冷连轧机第四机架闭环反馈控制进行深入研究,根据对偶法采用C语言开发出基于多变量最优化闭环反馈计算程序并将其嵌入到可编程逻辑控制器(Programmable logic controller,PLC)中,开发出自主的基于多变量最优化闭环反馈控制模块。由该模块计算的闭环反馈平直度执行机构调节量与采用Matlab工具箱Quadprog函数计算结果一致,计算精度高。     

Nonlinear Model-Based Predictive Control Using a Generalised Hammerstein Model and its Application to a Semi-Batch Reactor

In recent years, much attention has been focused upon predictive control of nonlinear systems. The implementation of such a control strategy for real processes has greatly improved their performance. This paper deals with a model-based predictivecontrol (MBPC) strategy using a generalised Hammerstein model and its application to the temperature control of a semibatch reactor. Both unconstrained and constrained adaptive control problems are considered. A simple identification method based on the weighted recursive least squares method (WRLS) is used to estimate the model parameters on-line. An indirect adaptive nonlinear controller is designed by combining the predictive controller with an indirect parameter estimation algorithm. This adaptive scheme has been applied for the control of a semi-batch chemical reactor. Experimental results show that the performance of the generalised Hammerstein MBPC (NLMBPC) was significantly better than that of a linear model predictive controller (LMBPC). ID="A1"Correspondance and offprint requests to: Dr F. M'sahli, Department of Electrical Engineering, ISETKH, Avenue Hadj Ali Soua, 5070, Ksar Hellal, Monastir, Tunisia. E-mail: msahli-fn@iyahoo.fr     

基于DSP的机械臂约束预测控制系统设计

针对机械臂的实时控制问题,基于约束预测控制,提出了一种机械臂实时运动控制方法。介绍了机械臂动力学模型并进行了线性化处理,以降低算法复杂度、保证实时性。设计了轨迹跟踪控制器和约束预测控制器,其中轨迹跟踪控制器采用最优反馈控制律,可确保机械臂按参考轨迹运动;而约束预测控制器则在考虑机械臂物理约束的情况下,为跟踪控制器提供最优参考轨迹。以DSP作为核心控制器,搭建了机械臂控制系统,同时给出了硬件和软件设计方法。以梯形和三次多项式轨迹为例,进行了系统功能测试,测试结果表明了所述控制系统的可行性和有效性。     

基于二次优化的节能控制器研究

针对建筑物中的设备能耗问题,通过对关键能耗设备采用二次优化型控制器,把节省能源建立在过程优化控制的内在因素中,该二次优化型控制器嵌有控制算法解释程序。研究结果表明,它能对基于IEC61131-3标准的控制算法组态程序解释运行,从而实现控制算法的组态和配置。     

Constrained incremental predictive controller design for a flexible joint robot

In this paper, an improved predictive control algorithm for controlling a typical nonlinear flexible-joint robot (FJR) with input constraint is proposed. The receding horizon algorithm, called generalized incremental predictive control (GIPC), utilizes both present and previous states rather than present states only. The GIPC algorithm includes the weighted difference of the current and the previous states and the summation of the control action increments. In order to illustrate the effectiveness of the proposed control strategy, it is implemented to the FJR and the results are compared with those of generalized predictive control (GPC). It is demonstrated that the proposed GIPC algorithm is more robust than the standard GPC method. Furthermore, the constrained GIPC algorithm using the quadratic programming removes instabilities caused by actuator saturation.     

基于PLC的步进电机控制方法研究

对于使用步进驱动器的步进控制系统,控制器对步进电机的控制关键在于控制脉冲信号的产生.以三菱FX2N - 48MT PLC为主控制器,介绍了使用该控制器产生控制脉冲信号的多种不同实现方法,进而实现对步进电机不同控制方法,给出了各种方法的具体实现,指出了各自的优劣.     

具有状态约束的电液伺服系统模型参考鲁棒自适应控制

针对电液伺服系统中的模型不确定性和状态约束问题,设计了一种模型参考鲁棒自适应控制(MRRAC)方法。将电液伺服系统的近似模型作为模型预测控制(MPC)的设计对象,在设计过程中考虑状态约束,并生成受约束的状态期望,作为后续伺服控制方法的参考指令。为了克服液压系统中的模型不确定性,基于反步法设计了鲁棒自适应控制器(RAC),实现了兼顾模型不确定性和状态约束的伺服控制。基于Lyapunov稳定性理论证明了所设计控制策略的闭环渐近稳定性,且系统所有信号均有界。仿真结果表明,控制器对于系统模型不确定性具有较强的鲁棒性,且可实现对指定状态的有效约束,充分验证了该控制策略的有效性。     

Predictive position and force control for shape memory alloy cylinders

In this paper, a linear lightweight electric cylinder constructed using shape memory alloy (SMA) is proposed. Spring SMA is used as the actuator to control the position and force of the cylinder rod. The model predictive control algorithm is investigated to compensate SMA hysteresis phenomenon and control the cylinder. In the predictive algorithm, the future output of the cylinder is computed based on the cylinder model, and the control signal is computed to minimize the error and power criterion. The cylinder model parameters are estimated by an online identification algorithm. Experimental results show that the SMA cylinder is able to precisely control position and force by using the predictive control strategy though the hysteresis effect existing in the actuator. The performance of the proposed controller is compared with that of a conventional PID controller.     

基于DSP的PLC运动功能的研究

为解决可编程逻辑控制器（PLC）传统CPU难以实现电机运动控制的问题,提出了一种基于梯形图翻译形式以及梯级执行机制的DSP．PLC架构,通过一套具有运动控制特点的指令集实现了可编程控制器的运动控制功能,并给出了运动控制的关键技术前后台动态（FBD）调度算法。实验结果表明,DSP—PLC构架既发挥了DSP高速处理的优势,又体现了PLC图形化的编程特色,且调度算法简单有效,可适用于电机运动控制系统。     

Improved design of constrained model predictive tracking control for batch processes against unknown uncertainties

In this paper, an improved constrained tracking control design is proposed for batch processes under uncertainties. A new process model that facilitates process state and tracking error augmentation with further additional tuning is first proposed. Then a subsequent controller design is formulated using robust stable constrained MPC optimization. Unlike conventional robust model predictive control (MPC), the proposed method enables the controller design to bear more degrees of tuning so that improved tracking control can be acquired, which is very important since uncertainties exist inevitably in practice and cause model/plant mismatches. An injection molding process is introduced to illustrate the effectiveness of the proposed MPC approach in comparison with conventional robust MPC.     

基于模糊集的流加发酵控制方法及其实现

乙醇浓度是发酵过程中重要的过程变量，直接影响着发酵过程的优化和控制。通过对酵母发酵生产谷胱甘肽（GSH）的过程机理分析选择了乙醇浓度作为主控变量，构建了相应的模糊控制器对发酵过程流加速率进行优化。利用WinCC（Windows control center）的全局脚本编辑器将模糊控制算法嵌入到PLC控制系统中，实现了对流加速率的模糊控制。实验表明．比较采用恒流加速率控制时的GSH产量，实施模糊控制后的GSH产量达到了2倍以上。     

双液注浆控制器的设计与研究

针对双液四缸的注浆模式,设计了基于PLC的注浆控制器。提出了采用一个流量反馈信号调节双液流量及比例的PID控制算法。利用AMESim建立了液压回路和控制回路模型进行仿真,验证了该算法的稳定性及可靠性,并给出本控制器硬件和软件的实现方法。     

Well-conditioned model predictive control

Model-based predictive control is an advanced control strategy that uses a move suppression factor or constrained optimization methods for achieving satisfactory closed-loop dynamic responses of complex systems. While these approaches are suitable for many processes, they are formulated on the selection of certain parameters that are ambiguous and also computationally demanding which makes them less suited for tight control of fast processes. In this paper, a new dynamic matrix control (DMC) algorithm is proposed that reduces inherent ill-conditioning by allowing the process prediction time step to exceed the control time step. The main feature, that stands in contrast with current DMC approaches, is that the original open-loop data are used to evaluate a "shifting factor" m in the controller matrix where m replaces the move suppression coefficient. The new control algorithm is practically demonstrated on a fast reacting process with better control being realized in comparison with DMC using move suppression. The algorithm also gives improved closed-loop responses for control simulations on a multivariable nonlinear process having variable dead-time, and on other models found in the literature. The shifting factor m is generic and can be effectively applied for any control horizon.     

Distributed synchronization control of complex networks with communication constraints

This paper is concerned with the distributed synchronization control of complex networks with communication constraints. In this work, the controllers communicate with each other through the wireless network, acting as a controller network. Due to the constrained transmission power, techniques such as the packet size reduction and transmission rate reduction schemes are proposed which could help reduce communication load of the controller network. The packet dropout problem is also considered in the controller design since it is often encountered in networked control systems. We show that the closed-loop system can be modeled as a switched system with uncertainties and random variables. By resorting to the switched system approach and some stochastic system analysis method, a new sufficient condition is firstly proposed such that the exponential synchronization is guaranteed in the mean-square sense. The controller gains are determined by using the well-known cone complementarity linearization (CCL) algorithm. Finally, a simulation study is performed, which demonstrates the effectiveness of the proposed design algorithm.     

基于预测控制理论的位置调节器软件设计

本文在预测控制的算法机理上给出了位置控制系统的预测模型，并在此基础上进一步介绍了基于预测控制理论的位置调节器程序的设计方法。     

基于嵌入式系统的自适应窑温控制器设计

提出了一种基于OK6410-B嵌入式开发平台的嵌入式自适应窑温控制器设计方法。该装置以自适应Smith算法为核心,采用传感器加嵌入式主板的硬件结构,红外线温度传感器负责温度采样,嵌入式主板负责参数计算和控制信号输出。在设计自适应Smith算法传递函数、进行硬件设备选型和连接后,还具体阐述了设备软件模块的实现方法。按该方案设计的控制器已得到实现,模拟仿真和工程实用证明:此种设计方案高效可靠,消除滞后时间和抗参数失配能力强,能够满足窑温控制的要求。     

Model predictive control for a class of systems with isolated nonlinearity

The paper is concerned with an overall convergent nonlinear model predictive control design for a kind of nonlinear mechatronic drive systems. The proposed nonlinear model predictive control results in the improvement of regulatory capacity for reference tracking and load disturbance rejection. The design of the nonlinear model predictive controller consists of two steps: the first step is to design a linear model predictive controller based on the linear part of the system at each sample instant, then an overall convergent nonlinear part is added to the linear model predictive controller to combine a nonlinear controller using error driven. The structure of the proposed controller is similar to that of classical PI optimal regulator but it also bears a set-point feed forward control loop, thus tracking ability and disturbance rejection are improved. The proposed method is compared with the results from recent literature, where control performance under both model match and mismatch cases are enlightened.     

Improving the feed-forward compensator in predictive control for setpoint tracking

Simple predictive control (MPC) algorithms produce a feed-forward compensator that may be a suboptimal choice. This paper gives some insights into this issue and simple means of modifying the feed-forward to produce a more systematic and optimal design. In particular, it is shown that the optimum procedure depends upon the underlying loop tuning and also that there are, as yet under utilised, potential benefits with regard to constraint handling procedures, which helps to improve the computational efficiency of the online controller implementation. A laboratory test in a programmable logic controller (PLC) was carried out to demonstrate the code on real hardware and the effectiveness of the solution.