scholarly journals Daytime/Nighttime Event-Based PI Control for the pH of a Microalgae Raceway Reactor

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 247 ◽  
Author(s):  
Enrique Rodríguez-Miranda ◽  
Manuel Beschi ◽  
José Luis Guzmán ◽  
Manuel Berenguel ◽  
Antonio Visioli
Keyword(s):  
Control Strategy ◽  
Pi Controller ◽  
Process Approach ◽  
Pi Control ◽  
Proportional Integral ◽  
Gas Consumption ◽  
Integral Controller ◽  
Proportional Integral Controller ◽  
Raceway Reactor ◽  
Event Based

In this paper, a new solution to improve the traditional control operation of raceway microalgae reactors is presented. The control strategy is based on an event-based method that can be easily coupled to a classical time-driven proportional-integral controller, simplifying the design process approach. The results of a standard Proportional-Integral (PI) controller, as well as of two event-based architectures, are presented in simulation and compared with each other and with traditional On/Off control. It is demonstrated that the event-based PI controller—operating during the whole day instead of only during daytime—achieves a better performance by reducing the actuator effort and saving costs related to gas consumption.

scholarly journals Evaluation of SIPIC01 and SIPIC02 on Motor Speed Control

2018 ◽  
Vol 152 ◽  
pp. 02010
Author(s):  
Kah Kit Wong ◽  
Choon Lih Hoo ◽  
Mohd Hardie Hidayat Mohyi
Keyword(s):  
Control System ◽  
Steady State ◽  
Dynamic Performance ◽  
Pi Controller ◽  
Settling Time ◽  
Motor Speed ◽  
Proportional Integral ◽  
Integral Controller ◽  
Proportional Integral Controller ◽  
Decoupling Effect

Due to its simplicity, Proportional-Integral (PI) controller still remains as the widely used controller for motor speed control system. However, PI controller exhibits windup phenomenon when the motor operates in a saturated state, which may cause degradation to the control system. In order to overcome the windup phenomenon, many researches have introduced various types of anti-windup methods such as the Conditioning Technique (CI), Tracking Back Calculation (TBC), Integral State Prediction (ISP), Steady-state Integral Proportional Integral Controller-01 (SIPIC01) and Steady-state Integral Proportional Integral Controller-02 (SIPIC02). These are anti-windup techniques with integral control switching mechanism, coupling of proportional gain, kp, and integral gain, ki. Due to the coupled kp and ki, tuning motor performance is a difficult task with short settling time without experiencing overshoot. SIPIC01 and SIPIC02 are robust anti-windup methods without a switching mechanism and exhibit decoupling feature. SIPIC01 and SIPIC02 have shown better dynamic performance compared to CI, TBC and ISP. However, SIPIC01 has not been compared to SIPIC02 in terms of their decoupling effect flexibility and dynamic performance. The decoupling effect was verified using MATLAB simulation, while the performance analysis was verified through hardware simulation and testing by using Scilab. The results obtained from the simulation showed that both SIPIC01 and SIPIC02 consist of decoupling features that allow a performance with coexistence of zero or minimum overshoot with short settling time. However, SIPIC02 consists of longer rise and settling time as compared to SIPIC01. Therefore, it can be concluded that SIPIC01 is better than SIPIC02 in term of dynamic performance.

scholarly journals A biomolecular proportional integral controller based on feedback regulations of protein level and activity

2018 ◽  
Vol 5 (2) ◽  
pp. 171966 ◽  
Author(s):  
Francis Mairet
Keyword(s):  
Redox Regulation ◽  
Feedback System ◽  
Pi Controller ◽  
Ammonium Uptake ◽  
Proportional Integral ◽  
Perfect Adaptation ◽  
Classical Integral ◽  
Integral Controller ◽  
Proportional Integral Controller ◽  
Living Organisms

Homeostasis is the capacity of living organisms to keep internal conditions regulated at a constant level, despite environmental fluctuations. Integral feedback control is known to play a key role in this behaviour. Here, I show that a feedback system involving transcriptional and post-translational regulations of the same executor protein acts as a proportional integral (PI) controller, leading to enhanced transient performances in comparison with a classical integral loop. Such a biomolecular controller—which I call a level and activity-PI controller (LA-PI)—is involved in the regulation of ammonium uptake by Escherichia coli through the transporter AmtB. The P II molecules, which reflect the nitrogen status of the cell, inhibit both the production of AmtB and its activity (via the NtrB-NtrC system and the formation of a complex with GlnK, respectively). Other examples of LA-PI controller include copper and zinc transporters, and the redox regulation in photosynthesis. This scheme has thus emerged through evolution in many biological systems, surely because of the benefits it offers in terms of performances (rapid and perfect adaptation) and economy (protein production according to needs).

Fuzzy Gain-Scheduling Proportional–Integral control for Improving the speed behavior of a three-phases induction motor

2016 ◽  
Vol 7 (4) ◽  
pp. 1161
Author(s):  
Hichem Othmani ◽  
D. Mezghani ◽  
A. Mami
Keyword(s):  
Transfer Function ◽  
Induction Machine ◽  
Gain Scheduling ◽  
Pi Controller ◽  
Integral Control ◽  
Proportional Integral ◽  
Integral Controller ◽  
Proportional Integral Controller ◽  
Proportional Integral Control ◽  
Set Up

In this article, we have set up a vector control law of induction machine where we tried different type of speed controllers. Our control strategy is of type Field Orientated Control (FOC). In this structure we designed a Fuzzy Gain-Scheduling Proportional–Integral (Pi) controller to obtain best result regarding the speed of induction machine. At the beginning we designed a Pi controller with fixed parameters. We came up to these parameters by identifying the transfer function of this controller to that of Broïda (second order transfer function). Then we designed a fuzzy logic (FL) controller. Based on simulation results, we highlight the performances of each controller. To improve the speed behaviour of the induction machine, we have designend a controller called “Fuzzy Gain-Scheduling Proportional–Integral controller” (FGS-PI controller) which inherited the pros of the aforementioned controllers. The simulation result of this controller will strengthen its performances.

Proportional-Integral Controller Assisted by GPI Observer for Microalgal Continuous Culture

2020 ◽  
Author(s):  
Viyils Sangregorio-Soto ◽  
Claudia L. Garzon-Castro ◽  
Gianfranco Mazzanti ◽  
Manuel Figueredo ◽  
John A. Cortes-Romero
Keyword(s):  
Continuous Culture ◽  
Proportional Integral ◽  
Integral Controller ◽  
Proportional Integral Controller

Limits of a simplified controller design based on integral plus dead time models

2018 ◽  
Vol 232 (6) ◽  
pp. 728-741 ◽  
Author(s):  
Mikuláš Huba ◽  
Igor Bélai
Keyword(s):  
Dead Time ◽  
Controller Design ◽  
Absolute Error ◽  
Higher Order ◽  
Smith Predictor ◽  
Proportional Integral ◽  
Overall Design ◽  
Error Measures ◽  
Integral Controller ◽  
Proportional Integral Controller

This article presents design and evaluation of filtered proportional–integral controllers and filtered Smith predictor–inspired constrained dead time compensators. Both are based on the integral plus dead time and on the first-order time delayed plant models. They are compared as for tuning simplicity, robustness and noise attenuation. Such a comparison, which presents a robustness test regarding the importance of the internal plant feedback approximation, may be carried out by performance measures built on deviations of the input and output transient responses from their ideal shapes. When combined with integral of absolute error measures of both solution types with the disturbance responses set as nearly equivalent, we can see that the filtered Smith predictor setpoint responses may be significantly faster than the filtered proportional–integral controller responses, more robust and, using higher-order filters, also sufficiently smooth. Furthermore, tuning of the possibly higher-order filters for filtered Smith predictor is simpler. Its overall design is more transparent and straightforward with respect to the control constraints, where the filtered Smith predictor requires some additional anti-windup measures.

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