Taylor级数在IMC-PID控制器参数整定中的应用

Taylor级数在工程计算中有着重要作用.通过对过程控制系统中包含纯滞后环节的近似处理,介绍了Taylor级数在IMC PID控制器参数整定中的应用.

时滞系统鲁棒IMC-PID控制器的研究

针对无精确模型情况下的FOPDT对象,首先通过一阶Pade近似获得系统的相乘不确定性界,然后采用内模控制器的设计步骤,以满足控制系统鲁棒性为条件,确定滤波时间常数的范围,最后,由等效的反馈结构,将内模控制方法引入PID控制器的设计,得到了其参数的明确解析结果。该方法避免了传统整定的复杂试凑过程,为时滞系统PID控制器设计提供了一条简单有效的途径。仿真结果验证了该方法的有效性。

IMC离散自适应系统

ＩＭＣ自适应控制系统是由ＩＭＣ控制器、跟踪模型和内模型构成的．介绍ＩＭＣ控制器的设计，控制器的设计是ＩＭＣ离散自适应系统的关键问题．根据鲁棒法要求，控制器必须同时对设定点响应与扰动响应均有良好的动态品质．

IMC based robust PID controller tuning for disturbance rejection

It is well-known that the IMC-PID controller tuning gives fast and improved set point response but slow disturbance rejection. A modification has been proposed in IMC-PID tuning rule for the improved disturbance rejection. For the modified IMC-PID tuning rule, a method has been developed to obtain the IMC-PID setting in closed-loop mode without acquiring detailed information of the process. The proposed method is based on the closed-loop step set point experiment using a proportional only controller with gain K_(c0). It is the direct approach to find the PID controller setting similar to classical Ziegler-Nichols closed-loop method. Based on simulations of a wide range of first-order with delay processes, a simple correlation has been derived to obtain the modified IMC-PID controller settings from closed-loop experiment. In this method, controller gain is a function of the overshoot obtained in the closed loop set point experiment. The integral and derivative time is mainly a function of the time to reach the first peak(overshoot). Simulation has been conducted for the broad class of processes and the controllers were tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison. The PID controller settings obtained in the proposed tuning method show better performance and robustness with other two-step tuning methods for the broad class of processes. It has also been applied to temperature control loop in distillation column model. The result has been compared to the open loop tuning method where it gives robust and fast response.

IMC-PID tuning method based on sensitivity specification for process with time-delay

To overcome the deficiencies addressed in the conventional PID control and improve the dynamic performance and robustness of the system, a simple design and parameters tuning approach of internal model control-PID （IMC-PID） controller was proposed for the first order plus time-delay （FOPTD） process and the second order plus time-delay （SOPTD） process. By approximating the time-delay term of the process model with the first-order Taylor series, the expressions for IMC-PID controller parameters were derived, and they had only one adjustable parameter 2 which was directly related to the dynamic performance and robustness of the system. Moreover, an analytical approach of selecting 2 was given based on the maximum sensitivity Ms. Then, the robust tuning of the system could be achieved according to the value of Ms. In addition, the proposed method could be extended to the integrator plus time-delay （IPTD） process and the first order delay integrating （FODI） process. Simulation studies were carried out on various processes with time-delay, and the results show that the proposed method could provide a better dynamic performance of both the set-point tracking and disturbance rejection and robustness against parameters perturbation.

PID Controller Design Based on the Time Domain Information of Robust IMC Controller Using Maximum Sensitivity

The IMC(Internal Model Control) controller based on robust tuning can improve the robustness and dynamic performance of the system.In this paper,the robustness degree of the control system is investigated based on Maximum Sensitivity(Ms) in depth.And the analytical relationship is obtained between the robustness specification and controller parameters,which gives a clear design criterion to robust IMC controller.Moreover,a novel and simple IMC-PID(Proportional-Integral-Derivative) tuning method is proposed by converting the IMC controller to PID form in terms of the time domain rather than the frequency domain adopted in some conventional IMC-based methods.Hence,the presented IMC-PID gives a good performance with a specific robustness degree.The new IMC-PID method is compared with other classical IMC-PID rules,showing the flexibility and feasibility for a wide range of plants.

离心选矿系统的IMC-PID串联解耦控制设计与实验研究

针对Knelson选矿机选矿过程的复杂性、主要控制量易波动等问题,在满足Knelson选矿机正常工作的前提下,借助辨识拟合方法构建离心选矿系统给矿环节的自衡过程数学模型,并设计了IMC-PID串联解耦控制器,通过对角矩阵解耦的方法获得需要的对角传递函数矩阵,将其作为的IMC-PID控制器的内部模型。将该控制器应用到Knelson选矿试验机,实验验证该控制器对离心选矿效果有明显的提升作用,并得到给矿环节两个重要变量(给矿流量和给矿浓度)对精矿富集比的影响规律,同时得出它们的最佳取值分别为0.66m^3/h和20%。