金矿氰化工艺中的MFA控制

介绍了金矿氰化工艺中的MFA控制，包括工作原理和系统设计，并举例说明。     

无模型自适应(MFA)控制

概述了一种新型的控制方法无模型自适应(MFA)控制。目的是对当前无模型自适应(MFA)控制有一个总体的认识,它无需数学建模以及复杂的人工参数整定即可控制时变、多变量等复杂过程。首先介绍了无模型自适应控制的性质及特征;结合燃烧过程的控制阐述无模型自适应控制理论的精髓;并和其他控制(如PID)方法作了比较。应用表明,无模型自适应控制可成功解决各种各样的控制问题,适应了现代化工业控制的要求,具有良好的应用与发展前景。     

基于Matlab-Simulink的MFA控制模块开发与仿真

无模型自适应控制(Model-free Adaptive Control,MFAC)是一种先进的控制策略。MFA控制器可以独立于受控对象进行独立的设计,而且具有很强的适应性和鲁棒性。介绍了无模型自适应控制的基本原理,在Matlab-Simulink平台上,给出了MFA控制器较为详细的开发过程,主要包括Simulink模块搭建以及嵌入模块中的S-function代码两部分。针对过程系统中普遍采用的二阶滞后模型进行了仿真研究,结果表明了MFA控制器的可行性和有效性。     

MFA控制器控制大时滞过程的实验研究

以大时滞过程为研究对象,对无模型自适应(MFA,M0del-freeAdaptive)控制器进行了仿真和实验研究,并与传统的PID控制器进行了比较,同时进行了鲁棒稳定性的研究。实验结果表明,无模型自适应控制器具有良好的输出跟踪性能,有很强的自适应能力和鲁棒性,能有效地控制复杂过程,特别在控制大时滞过程方面与传统的PID控制器相比,有着明显的优越性。     

金氰化浸出过程建模及实时优化自适应策略

以金氰化浸出过程为背景,基于物料守恒方程建立动态机理模型,用Tikhonov正则化方法估计动力学反应速度,进而辨识模型未知参数,有效降低了测量噪声对估计及辨识结果的影响;采用实时优化约束自适应方法减小模型参数失配对优化结果的影响.仿真结果表明,在模型参数失配时,所提出的方法仍能收敛到实际过程的最优设定点,不必求实际数据梯度,且受噪声影响小,便于实际应用,为湿法冶金全流程优化控制的顺利实施奠定了基础.     

金氰化浸出过程的自优化控制

针对湿法冶金金氰化浸出过程的实时优化问题,提出一个自优化控制方案.基于系统的参数不确定模型,选择并求解输出变量的线性组合为被控变量,在反馈控制器作用下跟踪其恒定设定值,实现浸出过程在不确定性扰动下的自优化控制.仿真结果验证了该控制方案的有效性:扰动产生时,系统的经济指标在常规控制作用下得到改善,并最终运行于真实的最优点附近,提高了浸出过程的生产效益.     

具有时滞的PH值中和过程模糊自适应控制

考察中和反应ＰＨ值实时演化过程的非线性特性，提出了一种能克服纯滞后特性的模糊自适应控制方案，仿真及应用表明，本方案可获得良好的控制效果。     

MFA技术的工作原理

无模型自适应控制,顾名思义,是一种无需进行繁琐和耗时的建模工作的自适应控制方法。对OEM供应商,这意味着更低的产品开发成本和更快的新品上市时间。为最终用户则带来更低的运营成本和更高的自控率。感谢MFA技术：     

金氰化浸出过程实时优化

本文以某湿法冶炼厂金氰化浸出过程为背景,建立了动态机理模型,为提高模型参数辨识精度,提出了基于Tikhonov正则化思想利用含噪声的浓度测量数据估计动力学反应速度的策略.为减小模型与实际过程不匹配对实时优化结果的影响,提出了基于对数–线性闸–罚函数和输出反馈的直接输入自适应方法,加入闸–罚函数后,该方法可以解决含有不等式约束的优化问题,将其应用到金氰化浸出过程实时优化中,仿真结果表明在输出测量值无噪声时,该方法能很快地局部收敛到实际过程的最优设定点;而当测量噪声较小或对目标函数影响较小时,该方法也显示出了优越的性能,而且只需要过程标称模型和实际输出,不需要求实际过程数据梯度,受测量噪声影响较小,更易于实际实施,这为湿法冶金全流程优化控制的顺利实施奠定了重要基础.     

On the convergence of a model reference adaptive control algorithm with unknown high frequency gain

A model reference adaptive control algorithm is shown not to be exponentially convergent when the high frequency gain of the plant is unknown. The implication is that such an algorithm will be lacking in some way in robustness.     

On the robust adaptive control of a contour-following robotic system

To demonstrate the force sensing and control, a possible model of a contour-following system is represented by a fourth-order linear continuous-time time-invariant system, in which stiffness k_t, robot natural frequency, ω_n, linear accommodation gain k_x, and angular accommodation gain k_φ are all constants obtained by measurement and experiment. This model works well for following a short contour. To satisfactorily follow a longer contour, k_t, ω_n, k_x and k_φ can be treated as unknown constants or time-varying variables. When they are considered as unknown constants, a robust model reference adaptive controller can be used to achieve both stability and tracking without having to know or find the true values of those constants, given bounded input or output disturbances and stable unmodeled dynamics. If ω_n is assumed to be a given constant but K_t, k_x, and k_φ are assumed to be unknown variables, then one has a linear time-varying plant and other types of model reference adaptive controllers have to be used to achieve the same purpose. In this paper, the schemes from various robust model reference adaptive control design will be studied and comparison and suggestions will also be made based on the simulation results for the contour-following robotic system mentioned above.     

基于模型参考自适应滑模控制的直线驱动伺服系统研究

为满足高速、高精确度和提高可靠性的需要,在新型机床中越来越多的采用直接线性驱动。在本文中,研究直线驱动伺服系统的模型和控制。首先,提出直线驱动的动态模型。其次,讨论通过对扰动、摩擦、齿槽力的补偿来改进直线驱动运动性能,引入模型参考自适应滑模控制器。最后,仿真结果表明,该方案可以获得较高的速度跟踪性能和鲁棒性能。     

Model Free Adaptive Control for a Class of Nonlinear Systems Using Quantized Information

This paper considers the stability of model free adaptive control systems with quantized information. Two quantized model free adaptive control (QMFAC) algorithms are proposed by using different signal quantization schemes, and here the logarithmic quantizer is introduced to decode these signals with a number of quantization levels. By using the sector bound method, the stability conditions of proposed QMFAC algorithms can be given and the effect of quantization error for such systems can also be discussed. It is shown that the tracking error under the QMFAC algorithm with system output quantized signal is proved to converge to a bound, and the bound depending on quantization density and desired trajectory. Thus, the tracking error under the QMFAC algorithm with tracking error quantized signal converges to zero. Two illustrative examples are given to validate the theoretical results.     

一类非线性大滞后系统的改进无模型自适应控制

针对工业过程中一类常见的非线性大滞后对象,基于伪偏导数(pseudo-partial-derivative,PPD)的概念动态线性化非线性系统,并利用跟踪.微分器预测系统未来时刻的输出,提出了一种改进的无模型自适应控制(improvedmodel-free adaptive control,IMFAC)算法.通过严格的理论推导,证明了新算法的BIBO稳定性和收敛性.仿真结果验证了该算法的有效性.     

Application of a robust model reference adaptive control algorithm to a nonlinear automotive actuator

Model reference adaptive control is a viable control method to impose the demanded dynamics on plants whose parameters are affected by large uncertainty. In this paper, we show by means of experiments that robust adaptive methods can effectively face nonlinearities that are common to many automotive electromechanical devices. We consider here, as a representative case study, the control of a strongly nonlinear automotive actuator. The experimental results confirm the effectiveness of the method to cope with unmodeled nonlinear terms and unknown parameters. In addition, the engineering performance indexes computed on experimental data clearly show that the robust adaptive strategy provides better performance compared with those given by a classical model-based control solution with fixed gains.     

Chattering‐free sliding mode control for a class of nonlinear mechanical systems

Second‐order sliding mode control (2‐smc) and dynamic sliding mode control (dsmc) eliminate the disturbing characteristic of chattering in static sliding mode control under the assumption that the derivative of the sliding surface is available or complex inequalities at the acceleration level can be constructed. In this paper, passivity‐based adaptive and non‐adaptive chattering‐free sliding mode controllers are proposed assuming that the upper bound of the norm of the derivative of the sliding surface is available, a weaker and easy to implement assumption in comparison to those of 2‐smc and dsmc. The closed‐loop system accounts explicitly for the invariance condition without reaching phase, and therefore for a desired transient response with global exponential convergence of tracking errors. Preliminary experiments are presented. Copyright © 2001 John Wiley & Sons, Ltd.     

On parameter convergence in adaptive control

It is well known that the parameter error as well as the model-plant mismatch error in a model reference adaptive scheme tends exponentially to zero iff a certain sufficient richness condition holds for signals inside the time-varying plant control loop. In this paper we give conditions on the reference signal (the exogenous input to the adaptive loop) — namely, that it have as many spectral lines as there are unknown parameters, in order to guarantee parameter convergence.     

A robust algorithm for model-following control of under-actuated systems,and its application to a non-holonomic robot and an aircraft

In this paper, we present an algorithm for model-following control of under-actuated systems. To make the algorithm robust, we try to suppress computation errors from approximations which are often encountered in the cases of applying the existing algorithms to the under-actuated systems. In this view, we present an algorithm without any kinds of approximations, even in the cases of under-actuated systems. Finally, we check the examples in which the proposed algorithm is applied to a non-holonomic robot and an aircraft.     

热电偶检定炉炉温模型参考自适应控制的研究

热电偶校检定炉在对热偶进行高温点的校验时,炉温难于稳定,主要原因在于控高温时加热时间较长环境温度产生较大变化,从而造成检定炉加热模型产生时变,导致控制器效果明显变差,本文利用模型参考自适应控制方法在线调整PID控制器参数以适应环境温度变化而造成的加热炉模型时变,试验结果表明该方法适应性良好,从而为热电偶检定炉的温度控制提供了新的方法。