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

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.

2012 ◽  
Vol 236-237 ◽  
pp. 356-359 ◽  
Author(s):  
Ling Quan ◽  
Hai Long Zhang

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.


2012 ◽  
Vol 605-607 ◽  
pp. 1496-1501
Author(s):  
Yun Song Li ◽  
Jie Meng ◽  
Ye He

Due to the structural characteristic, the dynamic performance of the high speed spindle is influenced by multi-coupled parameters. Conventional control method can’t attain the satisfied control result. So the view of internal model decoupling control of high speed motorized spindle is put forward, which can improve the performance of vector control system. In this paper, mathematical model based on internal model control of high speed spindle is set up. And voltage and current of stator are decoupled. At last, through simulation, it is proved that the method can improve the control effect and has better robustness, dynamic characteristic. Therefore, internal model decoupling control of high speed spindle is feasible and effective.


2020 ◽  
Vol 53 (5-6) ◽  
pp. 841-849 ◽  
Author(s):  
Sheng Wu ◽  
Ziwei Li ◽  
Ridong Zhang

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.


2020 ◽  
Vol 42 (14) ◽  
pp. 2733-2743
Author(s):  
Jiqiang Tang ◽  
Tongkun Wei ◽  
Qichao Lv ◽  
Xu Cui

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.


2019 ◽  
Vol 41 (13) ◽  
pp. 3637-3650 ◽  
Author(s):  
Imen Saidi ◽  
Nahla Touati ◽  
Ahmed Dhahri ◽  
Dhaou Soudani

This paper focuses on a challenging problem in the internal model control (IMC) strategy: the model inversion to design the IMC controller for non-square systems. Several existing approaches for the synthesis of a specific inversion of the identified model will be presented in this paper to deal with the differences between the system’s inputs and outputs numbers. The non-square effective relative gain is firstly presented. It consists of the measurement of interactions between the loops of the system in order to square the system and make it invertible. The equivalent transfer function method is presented as well. It is based on tuning the pseudo-inverse of the process to design the internal model controller. These methods are then compared with a novel proposed model inversion approach based on virtual outputs method. Virtual adding is considered in order to obtain an invertible square transfer matrix to design the internal model controller. This simple yet effective method ensures robust control performance. Its efficiency and availability, as compared with other presented methods, is illustrated through simulations on an overactuated system with three inputs/two outputs.


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