scholarly journals Disturbance rejection using IMC tuned PID controller with improved filter

2020 ◽  
Vol 20 (3) ◽  
pp. 1261
Author(s):  
B. Mabu Sarif ◽  
D. V. Ashok Kumar ◽  
M. Venu Gopala Rao
Keyword(s):  
Disturbance Rejection ◽  
Pid Controller ◽  
Industrial Applications ◽  
Internal Model Control ◽  
Exceptional Set ◽  
Suggested Approach ◽  
Set Point ◽  
Point Tracking ◽  
Model Control ◽  
Maximal Sensitivity

<p>IMC-PID controllers supply exceptional set point tracking but slow<br />disturbance refutation, because of introduction of slow process pole<br />introduced by the conventional filter. Disturbance rejection is important in<br />many industrial applications over set point tracking. An enhanced IMC filter<br />cascaded with PID controller with Internal Model Control Tuning System<br />(IMC-PID) is presented right now for efficient disruption rejection and<br />reliable first order process operation with time delay (FOPTD). The optional<br />filter does away with the sluggish dominant pole. The present learning shows<br />that the recommended IMC filter provide excellent trouble rejection<br />irrespective of where the trouble enters the procedure and provide high-<br />quality robustness to duplicate deviation in surroundings of accepting in<br />difference with other method cited in the text. Reenactment study was led to<br />show the feasibility of the suggested approach on processes with different 0/r ratios by measuring the controller parameters while retaining the same<br />robustness as regards maximal sensitivity. His efficiency of the closed loops<br />was assessed utilizing integral error parameters. Viz. ISE, ITAE, IAE. The<br />recommended filter provides excellent response pro lag dominant processes.</p>

Extended state observer based fractional order controller design for integer high order systems

2021 ◽  
pp. 095440622110621
Author(s):  
Rachid Mansouri ◽  
Maamar Bettayeb ◽  
Ubaid M Al-Saggaf ◽  
Abdulrahman U Alsaggaf ◽  
Muhammad Moinuddin
Keyword(s):  
Fractional Order ◽  
Disturbance Rejection ◽  
State Observer ◽  
Internal Model Control ◽  
Extended State Observer ◽  
Extended State ◽  
Set Point ◽  
Point Tracking ◽  
Model Control ◽  
Fractional Order Controller

In this paper, based on the extended state observer (ESO) and on a fractional order controller (FOC), composed of an integer order PID cascaded with a fractional order filter (FOF), a new control scheme for an n th order integer plant is proposed. The ESO is used to estimate and cancel the unknown internal dynamics and the external disturbance. Afterwards, an FOC is designed to resolve the set-point tracking problem. An analytical and systematic method is proposed to design the FOC. This method is based on the Internal Model Control (IMC) and the Bode’s Ideal Transfer Function (BITF). Therefore, the proposed control structure improves the robustness and performance of the traditional linear active disturbance rejection control (LADRC), especially for the open-loop gain variation. In addition, since the system be controlled is an n th order, a general form of the BITF is also proposed. Numerical simulations on a nonlinear model and experimental results on a cart-pendulum system design illustrate the effectiveness of the suggested ESO-PID-FOF scheme for the disturbance rejection, the set-point tracking and robustness. A comparison with the results obtained using the standard LADRC is also presented.

scholarly journals A Modified 2-DOF Control Framework and GA Based Intelligent Tuning of PID Controllers

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 423
Author(s):  
Gun-Baek So
Keyword(s):  
Disturbance Rejection ◽  
Pid Controller ◽  
Weighting Function ◽  
Pid Controllers ◽  
Set Point ◽  
Tuning Method ◽  
Point Tracking ◽  
Load Disturbance ◽  
Control Framework ◽  
Feedforward Controller

Although a controller is well-tuned for set-point tracking, it shows poor control results for load disturbance rejection and vice versa. In this paper, a modified two-degree-of-freedom (2-DOF) control framework to solve this problem is proposed, and an optimal tuning method for the pa-rameters of each proportional integral derivative (PID) controller is discussed. The unique feature of the proposed scheme is that a feedforward controller is embedded in the parallel control structure to improve set-point tracking performance. This feedforward controller and the standard PID con-troller are combined to create a new set-point weighted PID controller with a set-point weighting function. Therefore, in this study, two controllers are used: a set-point weighted PID controller for set-point tracking and a conventional PID controller for load disturbance rejection. The parameters included in the two controllers are tuned separately to improve set-point tracking and load dis-turbance rejection performances, respectively. Each controller is optimally tuned by genetic algo-rithm (GA) in terms of minimizing the IAE performance index, and what is special at this time is that it also tunes the set-point weighting parameter simultaneously. The simulation results performed on four virtual processes verify that the proposed method shows better performance in set-point tracking and load disturbance rejection than those of the other methods.

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.

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.

Simplified tuning of IMC based modified smith predictor for UFOPDT processes

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Somak Karan ◽  
Chanchal Dey
Keyword(s):  
Closed Loop ◽  
Performance Enhancement ◽  
Chemical Reactor ◽  
Internal Model Control ◽  
Smith Predictor ◽  
Tuning Parameter ◽  
Set Point ◽  
Point Tracking ◽  
Model Control ◽  
Modified Smith Predictor

AbstractA simplified tuning guideline for internal model control (IMC) based modified Smith predictor technique is reported here for unstable lag dominated first-order processes with dead time (UFOPDT). Pole location in right half section of s-plane signifies the unstable behaviour of UFOPDT processes. Mostly, chemical processes like isothermal chemical reactor, bioreactor, dimerization reactor, fluid catalytic cracker etc. are found to be lag dominated and unstable along with considerable time delay. Smith predictor technique based control methodology is considered to be a well-accepted approach for such cases. However, conventional Smith predictor technique is not capable enough for controlling UFOPDT processes. Whereas modified Smith predictor is found to be quite competent in such cases as its design involves more than one controller. Modified Smith predictor structure is capable to provide desirable closed loop response during set point tracking along with the load recovery phases. To mitigate the tuning complexity of multiple controllers involved in modified Smith predictor designing, suggested IMC structure employs single tuning parameter λ i.e. closed loop time constant for all three controllers concerned. Noticeable performance enhancement is reported by the proposed scheme as no overshoot is observed during set point tracking. Moreover, smooth and efficient load rejection behaviour is also obtained. Supremacy of the proposed tuning is established through closed loop performance comparison with others’ reported modified Smith predictor based tuning relations for chemical reactor and bioreactor in terms of performance indices as well as stability margins.

PID Controller Response to Set-Point Change in DC-DC Converter Control

2016 ◽  
Vol 7 (2) ◽  
pp. 294 ◽  
Author(s):  
Oladimeji Ibrahim ◽  
Nor Zaihar B Yahaya ◽  
Nordin Saad
Keyword(s):  
Disturbance Rejection ◽  
Pid Controller ◽  
Supply Voltage ◽  
Control Unit ◽  
Voltage Regulation ◽  
Power Converter ◽  
Point Change ◽  
Set Point ◽  
Circuit Elements ◽  
Tuning Methods

Power converter operations and efficiency is affected by variation in supply voltage, loads current, circuit elements, ageing and temperature.  To meet the objective of tight voltage regulation, power converters circuit module and the control unit must be robust to reject disturbances arising from supply, load variation and changes in circuit elements. PID controller has been the most widely used in power converter control. This paper presents studies of robustness of PID controller tuning methods to step changes in the set point and disturbance rejection in power converter control. A DC-DC boost converter was modelled using averaged state-space mothod and PID controllers were designed with five different tuning methods. The study reveals the transient response and disturbance rejection capability of each tuning methods for their suitability in power supply design applications.

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