Standard genetic algorithms （SGAs） are investigated to optimise discrete-time proportional-integral-derivative （PID） con- troller parameters, by three tuning approaches, for a multivariable glass furnace process w...Standard genetic algorithms （SGAs） are investigated to optimise discrete-time proportional-integral-derivative （PID） con- troller parameters, by three tuning approaches, for a multivariable glass furnace process with loop interaction. Initially, standard genetic algorithms （SGAs） are used to identify control oriented models of the plant which are subsequently used for controller optimisa- tion. An individual tuning approach without loop interaction is considered first to categorise the genetic operators, cost functions and improve searching boundaries to attain the desired performance criteria. The second tuning approach considers controller parameters optimisation with loop interaction and individual cost functions. While, the third tuning approach utilises a modified cost function which includes the total effect of both controlled variables, glass temperature and excess oxygen. This modified cost function is shown to exhibit improved control robustness and disturbance rejection under loop interaction.展开更多
A controller based on a PID neural network （PIDNN） is proposed for an arc welding power source whose output characteristic in responding to a given value is quickly and intelligently controlled in the welding proces...A controller based on a PID neural network （PIDNN） is proposed for an arc welding power source whose output characteristic in responding to a given value is quickly and intelligently controlled in the welding process. The new method syncretizes the PID control strategy and neural network to control the welding process intelligently, so it has the merit of PID control rules and the trait of better information disposal ability of the neural network. The results of simulation show that the controller has the properties of quick response, low overshoot, quick convergence and good stable accuracy, which meet the requirements for control of the welding process.展开更多
A multilayered control design approach is proposed here. Starting with the Dissolved Oxygen (DO) control loop in the last aerated tank, the control of the recirculation sludge is added next. Once the limitations of th...A multilayered control design approach is proposed here. Starting with the Dissolved Oxygen (DO) control loop in the last aerated tank, the control of the recirculation sludge is added next. Once the limitations of this two-loop control strategy are highlighted, a cascade control loop is proposed. This cascade control is further enhanced by a feed-forward control action that makes use of influent ammonia concentration. The resulting cascade+feedforward control configuration achieves satisfactory nitrogen removal for the three influent operating conditions (dry, rain and storm.)展开更多
利用SIEMENS公司S7-200系列PLC作为控制器,凭借其强大的PID指令和较强的浮点数计算能力,实现复杂过程控制实验的设计与研究,并使用SIEMENS公司软件系统Win CC(Windows Control Center)进行上位机监控和过程控制数据的保存。本文对S7-20...利用SIEMENS公司S7-200系列PLC作为控制器,凭借其强大的PID指令和较强的浮点数计算能力,实现复杂过程控制实验的设计与研究,并使用SIEMENS公司软件系统Win CC(Windows Control Center)进行上位机监控和过程控制数据的保存。本文对S7-200系列PLC的PID应用进行了分析,根据过程控制系统提出的总体要求和技术指标,对液位、压力、流量、温度等过程控制实验曲线进行分析,阐述PID算法各个环节的作用,总结PID的实验整定方法,以及PID整定方法选用的原则。展开更多
In this paper a trial has been made to design a simple self-tuning LabVIEW-based PID controller. The controller uses an open-loop relay test, calculates the tuned parameters in an open loop mode of operation before it...In this paper a trial has been made to design a simple self-tuning LabVIEW-based PID controller. The controller uses an open-loop relay test, calculates the tuned parameters in an open loop mode of operation before it updates controller parameters and runs the process as a closed-loop system. The controller reacts on a persistent offset error value as a result of load disturbance or a set point change. Practical results show that such a controller may be recommended to control a variety of industrial processes. A GUI was developed to facilitate control-mode selection, the setting of controller parameters, and the display of control system variables. GUI makes it possible to put the controller in manual or self-tuning mode.展开更多
文摘Standard genetic algorithms （SGAs） are investigated to optimise discrete-time proportional-integral-derivative （PID） con- troller parameters, by three tuning approaches, for a multivariable glass furnace process with loop interaction. Initially, standard genetic algorithms （SGAs） are used to identify control oriented models of the plant which are subsequently used for controller optimisa- tion. An individual tuning approach without loop interaction is considered first to categorise the genetic operators, cost functions and improve searching boundaries to attain the desired performance criteria. The second tuning approach considers controller parameters optimisation with loop interaction and individual cost functions. While, the third tuning approach utilises a modified cost function which includes the total effect of both controlled variables, glass temperature and excess oxygen. This modified cost function is shown to exhibit improved control robustness and disturbance rejection under loop interaction.
基金National Nature Science Foundation of China (No.50575074)
文摘A controller based on a PID neural network （PIDNN） is proposed for an arc welding power source whose output characteristic in responding to a given value is quickly and intelligently controlled in the welding process. The new method syncretizes the PID control strategy and neural network to control the welding process intelligently, so it has the merit of PID control rules and the trait of better information disposal ability of the neural network. The results of simulation show that the controller has the properties of quick response, low overshoot, quick convergence and good stable accuracy, which meet the requirements for control of the welding process.
文摘A multilayered control design approach is proposed here. Starting with the Dissolved Oxygen (DO) control loop in the last aerated tank, the control of the recirculation sludge is added next. Once the limitations of this two-loop control strategy are highlighted, a cascade control loop is proposed. This cascade control is further enhanced by a feed-forward control action that makes use of influent ammonia concentration. The resulting cascade+feedforward control configuration achieves satisfactory nitrogen removal for the three influent operating conditions (dry, rain and storm.)
文摘利用SIEMENS公司S7-200系列PLC作为控制器,凭借其强大的PID指令和较强的浮点数计算能力,实现复杂过程控制实验的设计与研究,并使用SIEMENS公司软件系统Win CC(Windows Control Center)进行上位机监控和过程控制数据的保存。本文对S7-200系列PLC的PID应用进行了分析,根据过程控制系统提出的总体要求和技术指标,对液位、压力、流量、温度等过程控制实验曲线进行分析,阐述PID算法各个环节的作用,总结PID的实验整定方法,以及PID整定方法选用的原则。
文摘In this paper a trial has been made to design a simple self-tuning LabVIEW-based PID controller. The controller uses an open-loop relay test, calculates the tuned parameters in an open loop mode of operation before it updates controller parameters and runs the process as a closed-loop system. The controller reacts on a persistent offset error value as a result of load disturbance or a set point change. Practical results show that such a controller may be recommended to control a variety of industrial processes. A GUI was developed to facilitate control-mode selection, the setting of controller parameters, and the display of control system variables. GUI makes it possible to put the controller in manual or self-tuning mode.
