Relay Feedback Based Autotuning PID Control of Paper Basis Weight in Paper Making Process

The brief arts and crafts of the ordinary fourdrinier are introduced first. After the intractable points of paper basis weight (BW) control are analyzed, an autotuning PID/PI control algorithm based on relay feedback identification is proposed, which has such advantages as simple parameter adjustment, little dependence on process model, strong robustness and easiness to implementation. And it is very suitable for controlling such processes as BW loop with large time delay.

Reliability Analysis on Repairable System with Dual Input Closed-Loop Feedback Link Considering Shutdown Correlation Based on Goal Oriented Methodology

Goal oriented( GO) methodology is a kind of success oriented system reliability analysis method and has been used widely.The repairable system with dual input closed-loop feedback link( DICLFL) considering shutdown correlation didn't make reliability analysis accurately based on existing GO methodology. So, a reliability analysis method used to deal with DICLFL considering shutdown correlation is provided based on GO methodology.Firstly, a new operator, which is used to describe DICLFL considering shutdown correlation,whose number is 1,is created and named as Type 9C operator. And then,the formulas of type 9C operator are derived based on Markov process theory. Finally,the new method presented in this paper is adopted to conduct the reliability analysis of an electro-hydraulic servo speed control system. The analysis result is compared with those of Monte Carlo simulation and fault tree analysis( FTA). The comparison results show that this new reliability analysis method based on GO methodology is feasible and meaningful for reliability analysis of repairable systems with DICLFL considering shutdown correlation.Meantime,it will be useful for more other applications.

Application of Single Neuron Adaptive PID Regulators with Auto-tuning Gain in Industrial Parameter(Pressure)Closed-loop Process Control Systems

A type of single neuron adaptive PID regulator with auto-tuning gain is proposed and applied to the work control of fans, waterpumps and air-pressers etc. in Handan Iron & Steel Compel China. The robusthess of induStrial parameter closed-loop process controlsystems is improved, and the work quality of the systems bettered.

基于STM32的密炼机自整定PID温控系统设计

针对密炼机温度控制系统中人工整定PID带来的系统响应不及时、误差大等问题,该文设计了一种基于STM32的自整定PID温度控制系统。对于电动阀只能单极性调节问题,通过设置适当的工艺点来控制继电输出。为提高震荡曲线的辨识,采用参数归一化方法计算震荡曲线的临界增益。考虑密炼机的工作环境和系统响应曲线的频率特性,加入带有临界滞环控制的继电控制方法,提高了特征参数的精确性,更好地整定了PID参数。应用结果表明,基于STM32的PID整定温度控制系统能够将温度误差控制在1℃左右,且控制时间相比于人工PID控制系统提高了30%,极大地满足了密炼机的温度控制要求,具有良好的实用价值。

Closed-loop identification of systems using hybrid Box–Jenkins structure and its application to PID tuning

The paper describes a closed-loop system identification procedure for hybrid continuous-time Box–Jenkins models and demonstrates how it can be used for IMC based PID controller tuning. An instrumental variable algorithm is used to identify hybrid continuous-time transfer function models of the Box–Jenkins form from discretetime prefiltered data, where the process model is a continuous-time transfer function, while the noise is represented as a discrete-time ARMA process. A novel penalized maximum-likelihood approach is used for estimating the discrete-time ARMA process and a circulatory noise elimination identification method is employed to estimate process model. The input–output data of a process are affected by additive circulatory noise in a closedloop. The noise-free input–output data of the process are obtained using the proposed method by removing these circulatory noise components. The process model can be achieved by using instrumental variable estimation method with prefiltered noise-free input–output data. The performance of the proposed hybrid parameter estimation scheme is evaluated by the Monte Carlo simulation analysis. Simulation results illustrate the efficacy of the proposed procedure. The methodology has been successfully applied in tuning of IMC based flow controller and a practical application demonstrates the applicability of the algorithm.

Reliability Analysis of Repairable System with Multiple Closed-Loop Feedbacks Based on GO Method

In order to solve the problem of reliability modeling and the analysis of complex systems with multiple closed-loop feedbacks,a new reliability analysis method for repairable systems with multiple closed-loop feedbacks is proposed based on the goal-oriented(GO)methodology.Firstly,the basic theories and advantages of GO method are introduced.Secondly,a type-24B multiple closed-loop feedback structure operator is proposed through GO method with its operation formula given,which expands the types of GO method operators and the application scope of their reliability analysis.Finally,taking a certain type of diesel engine fuel supply system an example,the quantitative and qualitative analysis is carried out through GO method,Monte Carlo simulation as well as FTA respectively.The availability results verify the availability of the proposed type-24B operator in the reliability analysis of multiple closed-loop feedback systems.The qualitative analysis results indicate the accuracy and usability of the GO method as a qualitative analysis method.

Fuzzy-PID controlled lift feedback fin stabilizer

Conventional PID controllers are widely used in fin stabilizer control systems, but they have time-variations, nonlinearity, and uncertainty influencing their control effects. A lift feedback fuzzy-PID control method was developed to better deal with these problems, and this lift feedback fin stabilizer system was simulated under different sea condition. Test results showed the system has better anti-rolling performance than traditional fin-angle PID control systems.

基于DDPG改进PID算法的堆肥翻堆作业反馈控制

在农业废弃物堆肥发酵过程中物料的含水率会发生变化,导致翻堆作业负荷的变化。而现有的翻堆作业主要通过人工操作,导致机器作业过程中作业效率低,容易产生故障。针对人工操作翻堆机作业时出现调控不精准的问题,通过试验构建翻堆机作业负荷与翻堆物料含水率、翻堆机行走速度关系模型,并结合翻堆机变频调速控制模型,利用DDPG(Deep Deterministic Policy Gradient)改进PID算法对翻堆作业调速系统进行优化控制。经过Simulink仿真结果表明,DDPG改进PID算法相比传统PID算法在超调量上减少6.7%,调节时间减少2.5 s,并且抗扰动与跟随性能均更优。翻堆作业现场测试结果表明:DDPG改进PID算法的控制方式相比传统PID算法超调量要降低4%、调节时间减少2 s,相比人工控制其调节时间减少6 s。

基于模糊规则的无刷直流电机免疫PID控制

无刷直流电机(Brushless DC Motor,BLDCM)是一种多变量、非线性的控制系统,采用经典的PID控制难以得到满意的控制效果。本文提出了一种新型的基于模糊规则的免疫PID控制器用于无刷直流电机的转速控制中。这种免疫PID控制根据T细胞的生物免疫反馈机理,包括决定应答速度的激活环节和决定稳定效果的抑制环节。用模糊规则来逼近其中的抑制环节,并与PID结合补偿其控制偏差。系统采用双闭环控制,内环为电流环,外环为速度环。Matlab仿真表明,系统超调量小,速度响应快,而且速度响应受电机参数变化影响小,各种外界干扰也得到了很好的抑制,具有较高的控制精度和较好的鲁棒性。通过以TI公司的TMS320F2812 DSP为基础进行的实验可以看出,较之传统PID控制,采用免疫PID控制在无刷直流电机的实时控制中取得了较好的实验效果,具有较好的动态和静态性能。

AtLoop PID自动整定软件包—原理与算法

本文阐述了PID自动整定软件包AtLoop的基本原理与算法．AtLoop适用于各种计算机控制系统PID调节器参数的自动整定，三个不同的软件分别适用于不同的用户和被控回路．AtLoop软件包已经在几个大型工业装置上成功使用了五年多．

PID控制器设计与参数整定方法综述

简要介绍了PID控制器的发展历程,综述PID控制器的设计与参数整定方法及其近期研究成果,并讨论了继电反馈方法的改进与扩展方法。通过分析PID控制器面临的问题与挑战,对PID控制器的发展进行了展望。

应变式微型精密压电驱动器的一体化设计及其PID控制

基于有限元分析设计了一种利用应变片进行位移反馈的微型精密压电驱动器。该驱动器采用位移放大机构对微小应变进行放大,通过测量应变电桥的输出间接地测量出驱动器的微小位移。标定实验显示该传感器的精度为80nm。虽然该应变反馈式压电驱动器是一种含有迟滞特性的复杂受控对象,但是在准静态条件下PID算法可以对其进行有效的闭环控制。分别进行了准静态的定位实验和跟踪实验,结果表明,PID控制算法对本驱动器的控制效果比较理想。在定位试验中,定位效果与开环相比有明显提高,定位误差不超过0.059μm;单频正弦信号跟踪误差不超过0.085μm;多频正弦信号跟踪误差不超过0.092μm。实验证明了该方法在准静态条件下的有效性。

利用位置式数字PID算法提高DFB激光器驱动电源稳定性

由于分布反馈式(DFB)激光器输出光功率受其激射电流的影响,为了保证其稳定的光功率输出,研制了基于位移式数字PID算法的高稳定性DFB激光器驱动电源。在硬件设计方面,该驱动电源主要由控制器模块、恒流源模块和保护电路模块组成。采用模拟PI深度负反馈环节有效地提高了驱动电流的稳定性。在软件方面,采用位置式数字PID算法,消除了实际驱动电流值与理论值之间的微小差异。利用该驱动电源,对中心波长为1 563.01 nm的DFB激光器做了驱动测试。实验表明,长期稳定性(>220 h)优于4×10-5,中心波长未出现漂移,为其在红外气体检测中提供了优越性能保障。

仪用PID参数自整定控制器设计与应用

传统的继电振荡PID参数自整定方法由于在整定期间要使系统处于临界振荡状态,并且整定周期较长,限制了在许多工业控制过程中的应用。介绍了一种基于开关阶跃响应算法的PID参数自整定控制器,通过在实际温度控制系统的应用,与继电振荡PID参数自整定算法以及ModiconPLC的PID参数自整定模块进行分析比较,证明该算法在安全性及整定时间上明显优于其他两种算法。

PMAC控制器中PID调节的应用

介绍了开放式运动控制器PMAC的结构及原理.阐述了PMAC的PID滤波器工作原理以及PID调节,并将此控制器作为实验磨床的数控系统.引入了前馈控制,构成了具有反馈和前馈的复合控制的系统结构,提高了系统的控制精度,实现了"无误差调节",使伺服特性达到刚性强、稳定性好、跟随误差小,进而实现精密加工的目的.通过对一些重要参数的调节,研究了PMAC控制器中PID的调节,获得合理的系统PID参数,达到良好的稳态和动态性能,最终实现跟随误差的最小化,为实现PMAC在精密加工中的应用打下基础.

基于PID控制器的HDRI系统的研究

HDRI系统是指进行高动态范围图像采集的成像系统。在使用空间光调制器进行反馈调制从而获取宽动态范围图像的系统中,由于未知景物光强范围很大,会导致反馈耗时或振荡。提出了一种将控制理论中的PID技术应用于反馈调制系统的调整方法。从PID的原理出发,根据工程应用的具体情况,简化了PID控制器的参数,得到了简单的PID控制器参数。通过数值仿真对PID控制器参数进行了充分的讨论,明确了这一参数的最优取值范围及取值原则。通过成像实验验证了这种PID控制参数的正确性。

基于LONWORKS现场总线的自整定PID控制系统

将PID自整定技术和现场总线技术有机地结合起来 ,实现了基于LONWORKS现场总线的PID自整定系统。自整定系统由两层组成 ,上层为PC计算机 ,下层为一个智能节点。它们之间通过LONWORKS现场总线进行通信。PC计算机给操作人员提供一个良好的人机界面 ,同时控制着整个PID参数自整定的过程。实验证明了该自整定系统的适用性和有效性 ,必将在工业过程控制中得到广泛的应用。

磁浮开关磁阻电机悬浮力的反馈线性化PID控制

推导磁浮开关磁阻电机轴向悬浮力数学模型。针对悬浮力控制的严重非线性,设计双环控制的轴向悬浮力控制器。反馈线性化控制将复杂的非线性对象转变为简单的线性控制系统,结合PID控制实现精确的位移跟踪,电流内环则实现了绕组实际电流对期望电流的跟踪控制。仿真与实验测试了系统在空载、负载、突加负载时的位移跟踪性能,验证了所提出控制方法的可行性及有效性。

基于遗传整定的模糊免疫PID控制器在液位控制系统中的应用研究

将遗传算法、模糊控制和免疫反馈机理与传统的PID控制相结合 ,提出了基于遗传整定的模糊免疫PID控制算法并将它应用在双容液位系统的控制中 实验结果表明 ,该控制方法的控制性能优于常规的PID控制 。

基于频域辨识的自整定PID控制器

提出了一种引入继电反馈的自整定ＰＩＤ控制器，在线测出过程对象两点的频率特性，辨识出二阶纯滞后的模型，基于相位、幅值裕度整定出ＰＩＤ参数。还介绍了该方法适应范围，仿真实验又仿真结果。