scholarly journals Diurnal and nocturnal pH control in microalgae raceway reactors by combining classical and event-based control approaches

2020 ◽  
Vol 82 (6) ◽  
pp. 1155-1165
Author(s):  
E. Rodríguez-Miranda ◽  
J. L. Guzmán ◽  
M. Berenguel ◽  
F. G. Acién ◽  
A. Visioli
Keyword(s):  
Experimental Tests ◽  
Ph Control ◽  
Control Algorithms ◽  
Pi Control ◽  
Night Time ◽  
Control Approach ◽  
Time Period ◽  
Reducing Costs ◽  
Raceway Reactor ◽  
Event Based

Abstract The pH control in raceway reactors is crucial for an optimal performance of the system. Classical pH control is exclusively performed during the daytime period for cost saving reasons. This paper demonstrates that pH can be controlled 24 hours a day by using both a continuous-based and an event-based control approach, being able to improve the system's performance and reducing costs at the same time. Thus, experimental tests on a raceway reactor for several days are presented to show a comparison between traditional control algorithms during the daytime period versus an event-based control approach operating during both daytime and night-time periods. As a result, the combination of classical PI control for the daytime period and the event-based control for the night-time period is presented as a promising pH control architecture in raceway reactors.

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.

Effective utilization of flue gases in raceway reactor with event-based pH control for microalgae culture

2014 ◽  
Vol 170 ◽  
pp. 1-9 ◽  
Author(s):  
A. Pawlowski ◽  
J.L. Mendoza ◽  
J.L. Guzmán ◽  
M. Berenguel ◽  
F.G. Acién ◽  
...  
Keyword(s):  
Ph Control ◽  
Flue Gases ◽  
Effective Utilization ◽  
Microalgae Culture ◽  
Raceway Reactor ◽  
Event Based

scholarly journals Modelling and pH Control in Raceway and Thin-Layer Photobioreactors for Wastewater Treatment

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1099
Author(s):  
María José Rodríguez-Torres ◽  
Ainoa Morillas-España ◽  
José Luis Guzmán ◽  
Francisco Gabriel Acién
Keyword(s):  
Wastewater Treatment ◽  
Thin Layer ◽  
Large Scale ◽  
Control Period ◽  
Ph Control ◽  
Thin Layers ◽  
Control Algorithms ◽  
Treatment Processes ◽  
Overall Performance ◽  
Reduction Of Co2

One of the most critical variables in microalgae-related processes is the pH; it directly determines the overall performance of the production system especially when coupling with wastewater treatment. In microalgae-related wastewater treatment processes, the adequacy of pH has a large impact on the microalgae/bacteria consortium already developing on these systems. For cost-saving reasons, the pH is usually controlled by classical On/Off control algorithms during the daytime period, typically with the dynamics of the system and disturbances not being considered in the design of the control system. This paper presents the modelling and pH control in open photobioreactors, both raceway and thin-layer, using advanced controllers. In both types of photobioreactors, a classic control was implemented and compared with a Proportional–Integral (PI) control, also the operation during only the daylight period and complete daily time was evaluated. Thus, three major variables already studied include (i) the type of reactors (thin-layers and raceways), (ii) the type of control algorithm (On/Off and PI), and (iii) the control period (during the daytime and throughout the daytime and nighttime). Results show that the pH was adequately controlled in both photobioreactors, although each type requires different control algorithms, the pH control being largely improved when using PI controllers, with the controllers allowing us to reduce the total costs of the process with the reduction of CO2 injections. Moreover, the control during the complete daily cycle (including night) not only not increases the amount of CO2 to be injected, otherwise reducing it, but also improves the overall performance of the production process. Optimal pH control systems here developed are highly useful to develop robust large-scale microalgae-related wastewater treatment processes.

Design and Implementation of an Event-Based RFID Middleware

2012 ◽  
pp. 110-131
Author(s):  
Angelo Cucinotta ◽  
Antonino Longo Minnolo ◽  
Antonio Puliafito
Keyword(s):  
Business Processes ◽  
Strong Impact ◽  
Rfid Technology ◽  
Application Development ◽  
Technological Level ◽  
Rfid Middleware ◽  
Reducing Costs ◽  
High Level ◽  
The Cost ◽  
Event Based

The downward trend in the cost of RFID technology is producing a strong impact on the industrial world that is using such powerful technology in order to rethink and optimize most of the existing business processes. In this sense, the chipless technology is playing a key role to facilitate the adoption of RFID in enterprises. All this implies the use of solutions that simplify the adoption of the continuously evolving RFID technology and allow keeping a high-level vision versus the specific technical details. In brief, it is mandatory to abstract the technological level and makes transparent the physical devices to the application level. The widespread use of the RFID technology also produces a large volume of data from many objects scattered everywhere, that have to be managed. In these complex scenarios, the RFID middleware represents an ideal solution that favors the technology integration, reducing costs for application development and introducing real benefits to the business processes. In this chapter, the authors describe the main features of our event-based RFID middleware and its powerful architecture. Their middleware is able to assure an effective process of technological abstraction, switching from a vision linked to the specific issues of interfacing devices (chipless tags, readers, sensor networks, GPS, WiFi, etc.) to the management of the event generated by each device. In brief, “event-based” means to integrate the management logic of different devices.

scholarly journals Mechatronic Control System for a Compliant and Precise Pneumatic Rotary Drive Unit

Actuators ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
Johannes T. Stoll ◽  
Kevin Schanz ◽  
Andreas Pott
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Mechanical Design ◽  
Control Algorithms ◽  
Field Oriented Control ◽  
Pneumatic Drive ◽  
Drive Unit ◽  
Control Approach ◽  
Human Robot Collaboration ◽  
Rotary Drive

Robots that enable safe human-robot collaboration can be realized by using compliant drive units. In previous works, different mechanical designs of compliant pneumatic rotary drive units with similar characteristics have been presented. In this paper, we present the overall control approach that we use to operate one of these compliant pneumatic rotary drive units. We explain the mechanical design and derive the differential equation that describes the dynamics of the system. In order to successfully operate a pneumatic drive unit with three or more working chambers, the torque specified by the controller has to be split up onto the working chambers. We transfer the well-known field-oriented control approach from electric motors to the investigated pneumatic drive unit to create such a torque mapping. Moreover, we develop optimized torque mappings that are tailored to work with this type of drive unit. Furthermore, we introduce and compare two control algorithms based on different implementations of state feedback to realize position control. Finally, we present the step responses that we achieve when we implement either one of the control algorithms in combination with the different torque mappings.

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