scholarly journals An improved 2-degree-of-freedom internal model proportional–integral–derivative controller design for stable time-delay processes

2020 ◽  
Vol 53 (5-6) ◽  
pp. 841-849 ◽  
Author(s):  
Sheng Wu ◽  
Ziwei Li ◽  
Ridong Zhang
Keyword(s):  
Time Delay ◽  
Internal Model ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Controller Design ◽  
Internal Model Control ◽  
Degree Of Freedom ◽  
Set Point ◽  
Point Tracking ◽  
Model Control

In this article, an enhanced 2-degree-of-freedom internal model control strategy for typical industrial processes with time-delay is developed. For the proposed controller, it is composed of an inner loop feedback controller which is designed based on the internal model control theory and a weighted set-point tracking controller. Note that the adjustment of set-point tracking performance and disturbance rejection characteristics can be decoupled by employing the developed strategy, which indicates that more degrees of freedom are obtained for the proposed controller design; thus, better ensemble performance and stronger robustness are anticipated by regulating these two controllers separately, which may not be achieved in the conventional internal model control method. Case studies on two kinds of stable processes with time-delay verify the effectiveness of the proposed scheme finally.

scholarly journals Modified two-degree-of-freedom Smith predictive control for processes with time-delay

2020 ◽  
Vol 53 (3-4) ◽  
pp. 691-697 ◽  
Author(s):  
Ziwei Li ◽  
Jianjun Bai ◽  
Hongbo Zou
Keyword(s):  
Time Delay ◽  
Predictive Control ◽  
Control Strategy ◽  
Disturbance Rejection ◽  
Control Method ◽  
Internal Model Control ◽  
Degree Of Freedom ◽  
Set Point ◽  
Point Tracking ◽  
Two Degree Of Freedom

This article proposes an improved two-degree-of-freedom Smith predictive control method for typical industrial control systems. Smith predictive control is a classic control strategy designed for systems with pure lag. As an extension of Smith predictive control, internal model control can solve the time-delay problem effectively and make the controller design simple. Based on the two control algorithms, an enhanced control method with modified control structure is developed in this paper. In the design scheme, the set-point tracking and the disturbance rejection characteristics are decoupled, such that the set-point tracking and disturbance rejection controllers can be designed independently to achieve better control performance. The obtained control strategy possesses simple and convenient parameter tuning procedures. The validity of the proposed scheme is verified through theoretical analysis and simulation comparison with other control methods, and the results indicate that the proposed strategy shows better performance on set-point tracking and disturbance rejection.

Max-Max Based Internal Model Control Method for Multivariable System with Time Delay

2012 ◽  
Vol 236-237 ◽  
pp. 356-359 ◽  
Author(s):  
Ling Quan ◽  
Hai Long Zhang
Keyword(s):  
Time Delay ◽  
Internal Model ◽  
Control Method ◽  
Controller Design ◽  
Design Method ◽  
Internal Model Control ◽  
Multivariable System ◽  
Model Control ◽  
Internal Model Controller ◽  
System With Time Delay

Multivariable system with time delay and coupling widely exist in industrial which may destroy the normal work of control system. An unconventional internal model controller design method will be introduced in this paper. The closed loop system can be decouple by calculate the inverse of transfer function matrix and the optimal diagonal decomposition matrix. Finally, this method was applied in a multivariable system with different time delays, the simulation results can show the effectiveness of this method.

scholarly journals Internal Model Control for Rank-Deficient System with Time Delays Based on Damped Pseudo-Inverse

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 264
Author(s):  
Meiying Jiang ◽  
Beiyan Jiang ◽  
Qi Wang
Keyword(s):  
Time Delay ◽  
Internal Model ◽  
Control Method ◽  
Dynamic Performance ◽  
Delay System ◽  
Internal Model Control ◽  
Damping Factor ◽  
Model Control ◽  
Value Decomposition ◽  
Pseudo Inverse

It is a challenge to design a satisfactory controller for a complex multivariable industrial system with minimal offsetting and a slow response. An internal model control method is proposed for rank-deficient systems with a time delay based on a damped pseudo-inverse. An internal model control was designed to obtain the desired dynamic characteristics of the system by transforming the time-delay system into a system without a time delay, following the Pade approximation approach. By introducing a damping factor, the internal model controller was designed based on a damped pseudo-inverse, since the inverse matrix of the rank-deficient system does not exist. Furthermore, a singular value decomposition was used to analyze the steady-state performance of the system. The selection of the damping factor was also presented, and a μ analysis was made to evaluate the stability of the system. To demonstrate the effectiveness of the proposed method, a crude distillation process with five inputs and four outputs was considered as an example. The simulation results illustrate that not only can the proposed strategy guarantee the system’s stability, but it also has a relatively good dynamic performance.

Stable control of the high-speeding magnetically suspended rotor based on extended state observer and two-degree freedom internal model control for control moment gyros with serious moving-gimbal effects

2020 ◽  
Vol 42 (14) ◽  
pp. 2733-2743
Author(s):  
Jiqiang Tang ◽  
Tongkun Wei ◽  
Qichao Lv ◽  
Xu Cui
Keyword(s):  
Internal Model ◽  
Feedback Linearization ◽  
Control Method ◽  
Fast Response ◽  
State Observer ◽  
Internal Model Control ◽  
Extended State Observer ◽  
Extended State ◽  
Control Moment ◽  
Model Control

For a magnetically suspended control moment gyro (MSCMG), which is an ideal attitude actuator for its large outputting control moment and fast response, the moving-gimbal effects due to the coupling between the moving gimbal and high-speeding rotor will make the magnetically suspended rotor (MSR) unstable. To improve control precision, both the dynamic model of MSR and the feedback linearization control are done to decouple tilting motion, and poles of the system are reconfigured to reduce control error. To suppress the varying disturbance moments caused by moving-gimbal effects, an extended state observer (ESO) is originally designed to estimate and compensate them timely and accurately. To improve system robustness, a two-degree freedom internal model control (2-DOF IMC) is researched to suppress model error. Compared with existing proportional integral derivative (PID) control method, simulations done on a single gimbal MSCMG with 200 N.m.s angular momentum indicated that this presented control method with ESO and 2-DOF IMC can suppress the moving-gimbal effects more effectively and make the rotor suspension more stable.

Robust Controllers for Pulse-Width-Modulated D.C./D.C. Converters Using Internal-Model-Control Design

1993 ◽  
Vol 207 (3) ◽  
pp. 127-134 ◽  
Author(s):  
D Garabandić ◽  
T Petrović
Keyword(s):  
Model Uncertainty ◽  
Pulse Width ◽  
Internal Model ◽  
Controller Design ◽  
Optimization Method ◽  
Internal Model Control ◽  
Linear Feedback ◽  
Pulse Width Modulated ◽  
Linear Feedback Controller ◽  
Model Control

A linear feedback controller for pulse-width-modulated d.c./d.c. regulator is designed using a frequency domain optimization method based on internal-model-control theory. This method aims to produce suboptimal low-order controllers which are ‘robust’, in the sense that the closed-loop system is guaranteed to meet stability objectives in the presence of model uncertainty. The small-signal model of a d.c./d.c. converter is used for the controller design. The model uncertainty description derived here is based on experiments and non-linear modelling. The result of the synthesis is a family of controllers, and each member of this family satisfies the robust control objectives. All controllers have a multi-loop structure including two feedback loops and one feedforward loop. A detailed design of the controller, including experimental results, is presented.

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