Tuning and comparison of design concepts applying Pareto optimality. A case study of Cholette bioreactor

[EN] The linear control PI (D) and its variants are control structures (design concepts) that are still used in industrial processes. The control engineer will prefer one over another according to a desired tradeoff among complexity and performance indices. Given that this exchange might be in conflict, an analisis using multiobjective optimisation tools could be interesting. With this perspective, different Pareto fronts from different design concetps are compared, enabling a global, and not punctual, performance comparison. In this work a global methodology for comparing design concepts in dfferent stages was developed. The first step was to establish a region of stability. In the second stage, the stability region was considered as a search space for the multiobjective optimization process, approximating a Pareto set and front. In the third stage, a multicriteria analysis of the Pareto fronts was carried out, together with the simulation in the time domain for the output and control signals. As case study to validate this proposal the Cholette’s biorreactor was selected. The proposed methodology allows a better understanding of a conceptual solution, justifies and determines the use of a design concept thus meeting the needs of the designer.[ES] El control lineal PI(D) y sus variantes, son estructuras de control (conceptos de diseño) que actualmente se siguen utilizando en procesos industriales. La elección de una estructura de control sobre otra reside en el intercambio de prestaciones entre complejidad y rendimiento. Dado que este intercambio de prestaciones normalmente estará en conflicto, un análisis desde el punto de vista multiobjetivo puede ser de interés. Desde tal perspectiva, se analizan frentes de Pareto de diferentes conceptos de diseño, con lo que se realiza una comparación global y no puntual de tales conceptos. En este trabajo se plantea una propuesta metodológica para dicha comparación en diferentes etapas. La primera, fue establecer una región de estabilidad. En la segunda etapa se consideró la región de estabilidad como espacio de búsqueda para el proceso de optimización multiobjetivo calculando un conjunto y frente de Pareto. En la tercera etapa se realizó un análisis multicriterio de los frentes de Pareto, junto con la simulación en el dominio del tiempo para las señales de salida y de control. Como caso de estudio para validar la propuesta se ha elegido el biorreactor de Cholette que presenta diferentes condiciones de operación. La metodología propuesta permite una mejor comprensión de una solución conceptual, justifica y determina el uso de un concepto de diseño cumpliendo así con las necesidades del diseñador.Torralba-Morales, L.; Reynoso-Meza, G.; Carrillo-Ahumada, J. (2020). Sintonización y comparación de conceptos de diseño aplicando la optimalidad de Pareto. Un caso de estudio del biorreactor de Cholette. Revista Iberoamericana de Automática e Informática industrial. 17(2):190-201. https://doi.org/10.4995/riai.2019.11424OJS190201172Ajmeri, M., Ali, A., 2015. Two degree of freedom control scheme for unstable processes with small time delay. ISA Transactions 56, 308-326. https://doi.org/10.1016/j.isatra.2014.12.007Aström, K., Hägglund, T., 2006. Advanced PID Control. Vol. 461. ISA-The Instrumentation, Systems, and Automation Society Research Triangle.Aström, K. J., Hägglund, T., 1995. PID Controllers: Theory, Design, and Tuning. Instrument Society of America, Research Triangle Park, NC.Carlos-Hernández, S., Sanchez, E. N., Béteau, J.-F., Jiménez, L. D., 2014. Análisis de un Proceso de Tratamiento de Efluentes para Producción de Metano. Revista Iberoamericana de Automatica e Informática Industrial RIAI 11 (2), 236 - 246. https://doi.org/10.1016/j.riai.2014.02.006Carrillo-Ahumada, J., Paramo-Calderón, D., Aparicio-Saguilán, A., Rodríguez Jimenes, G., García-Alvarado, M., 2014. Approach of a Measurement of Linearized Representation of a Nonlinear System. Application to (Bio)Chemical reactors. Revista Mexicana de Ingenier'ıa Qu'ımica 13 (2), 631-647.Carrillo-Ahumada, J., Reynoso-Meza, G., García-Nieto, S., Sanchis, J., García Alvarado, M., 2015. Sintonización de controladores Pareto-óptimo robustos para sistemas multivariables. Aplicación en un helicóptero de 2 grados de libertad. Revista Iberoamericana de Automática e Informática industrial 12, 177-188. https://doi.org/10.1016/j.riai.2015.03.002Carrillo-Ahumada, J., Rodríguez-Jimenes, G., García-Alvarado, M., 2011. Tunning optimal-robust linear MIMO controllers of chemical reactors by using Pareto optimality. Chemical Engineering Journal 174 (1), 357 - 367. https://doi.org/10.1016/j.cej.2011.09.007Chen, Z., Yuan, X., Ji, B., Wang, P., Tian, H., 2014. Design of a fractional order PID controller for hydraulic turbine regulating system using chaotic non-dominated sorting genetic algorithm II. Energy Conversion and Management 84, 390 - 404. https://doi.org/10.1016/j.enconman.2014.04.052Chidambaram, M., Reddy, G., 1996. Nonlinear control of systems with input and output multiplicities. Computers and Chemical Engineering 20 (3), 295 - 299. https://doi.org/10.1016/0098-1354(95)00019-4Darby, M. L., Nikolaou, M., 2012. MPC: Current practice and challenges. Control Engineering Practice 20 (4), 328 - 342. https://doi.org/10.1016/j.conengprac.2011.12.004García-Alvarado, M., Ruiz-López, I., Torres-Ramos, T., 2005. Tuning of multi-variate PID controllers based on characteristic matrix eigenvalues, Lyapunov functions and robustness criteria. Chemical Engineering Science 60 (4), 897 - 905. https://doi.org/10.1016/j.ces.2004.09.047Gómez, L., Botero, H., Álvarez, H., di Sciascio, F., 2015. Análisis de la Controlabilidad de Estado de Sistemas Irreversibles Mediante teoría de conjuntos. Revista Iberoamericana de Automática e Informática Industrial RIAI 12 (2), 145 - 153.https://doi.org/10.1016/j.riai.2015.02.002Hernández, F., Herrera Fernández, F., 03 2012. Identificación Inteligente de un Proceso Fermentativo Usando el Algoritmo GMDH Modificado. Revista Iberoamericana de Automática e Informática Industrial RIAI 9, 313. https://doi.org/10.1016/j.riai.2011.11.001Huang, H., Chen, C., 1999. Autotuning of PID Controllers for Second Order Unstable Process Having Dead Time. Journal of Chemical Engineering of Japan 32 (4), 486-497. https://doi.org/10.1252/jcej.32.486Huilcapi, V., Blasco, X., Herrero, J. M., Reynoso-Meza, G., 2019. A loop pairing method for multivariable control systems under a multi-objective optimization approach. IEEE Access 7, 81994-82014. https://doi.org/10.1109/ACCESS.2019.2923654Ibarra-Junquera, V., Rosu, H., 2007. PI-controlled bioreactor as a generalized Liénard system. Computers and Chemical Engineering 31 (3), 136-141. https://doi.org/10.1016/j.compchemeng.2006.05.023Indranil, P., Saptarshi, D., 2015. Fractional-order load-frequency control of interconnected power systems using chaotic multi-objective optimization. Applied Soft Computing 29, 328 - 344. https://doi.org/10.1016/j.asoc.2014.12.032Jhunjhunwala, M. K., Chidambaram, M., 2001. PID Controller tunning for Unstable Systems by Optimization Method. Chemical Engineering Communications. 185 (1), 91-113. https://doi.org/10.1080/00986440108912857Márquez-Rubio, J., del Muro-Cuéllar, B., 2010. Control basado en un esquema observador para sistemas de primer orden con retardo. Revista Mexicana de Ingeniería Química 09, 43-52.Mattson, C. A., Messac, A., 2005. Pareto Frontier Based Concept Selection Under Uncertainty, with Visualization. Optimization and Engineering 6 (1), 85-115. https://doi.org/10.1023/B:OPTE.0000048538.35456.45Mora, L. A., Amaya, J. E., 2017. Un nuevo Método de Identificación Basado en la Respuesta Escalón en Lazo Abierto de Sistemas Sobre-amortiguados. Revista Iberoamericana de Automática e Informática industrial 14 (1), 31- 43. https://doi.org/10.1016/j.riai.2016.09.006Naranjani, Y., Sardahi, Y., Chen, Y., Sun, J.-Q., 2015. Multi-objective optimization of distributed-order fractional damping. Communications in Nonlinear Science and Numerical Simulation 24 (1), 159 - 168. https://doi.org/10.1016/j.cnsns.2014.12.011Normey-Rico, J., Camacho, E., 2009. Unified approach for robust dead-time compensator design. Journal of Process Control 19 (1), 38-47.https://doi.org/10.1016/j.jprocont.2008.02.003O'Dwyer, A., 2009. Handbook of PI and PID controller tuning rules. IFAC Proceedings Volumes 57. https://doi.org/10.1142/p575Padma, S., Chidambaram, M., 2002. Identification of Unstable transfer Model with a Zero by Optimization method. Journal of the Indian Institute of Science 82 (5 & 6), 219-225.Padma, S., Chidambaram, M., 2005. Set Point Weighted PID Controllers For Unstable Systems. Chemical Engineering Communications 192 (1), 1-13. https://doi.org/10.1080/00986440590473137Rajinikanth, V., Latha, K., 2012a. Controller Parameter Optimization for Nonlinear Systems Using Enhanced Bacteria Foraging Algorithm. Applied Computational Intelligence and Soft Computing 2012. https://doi.org/10.1155/2012/214264Rajinikanth, V., Latha, K., 2012b. I-PD Controller Tuning for Unstable System Using Bacterial Foraging Algorithm: A Study Based on Various Error Criterion. Applied Computational Intelligence and Soft Computing 2012. https://doi.org/10.1155/2012/329389Reynoso-Meza, G., 2014. Controller tuning by means of evolutionary multiobjective optimization: a holistic multiobjective optimization design procedure. Ph.D. thesis, Universitat Politècnica de València, http://hdl.handle.net/10251/38248.Reynoso-Meza, G., Carrillo-Ahumada, J., Boada, Y., Picó, J., 2016. PID controller tuning for unstable processes using a multi-objective optimisation design procedure. IFAC-PapersOnLine 49 (7), 284 - 289. https://doi.org/10.1016/j.ifacol.2016.07.287Reynoso-Meza, G., Garcia-Nieto, S., Sanchis, J., Blasco, F. X., 2012. Controller tuning by means of multi-objective optimization algorithms: A global tuning framework. IEEE Transactions on Control Systems Technology 21 (2), 445-458. https://doi.org/10.1109/TCST.2012.2185698Reynoso-Meza, G., Sanchis, J., Blasco, X., Martínez, M., 2013. Algoritmos Evolutivos y su empleo en el ajuste de controladores del tipo PID: Estado Actual y perspectivas. Revista Iberoamericana de Automática e Informática Industrial RIAI 10 (3), 251-268. https://doi.org/10.1016/j.riai.2013.04.001Samad, T., Feb 2017. A survey on industry impact and challenges thereof [technical activities]. IEEE Control Systems Magazine 37 (1), 17-18. https://doi.org/10.1109/MCS.2016.2621438Sanchez, A., Rotstein, G., Alsop, N., Bromberg, J., Gollain, C., Sorensen, S., Macchietto, S., Jakeman, C., 2002. Improving the development of eventdriven control systems in the batch processing industry. A case study. ISA Transactions 41 (3), 343 - 363. https://doi.org/10.1016/S0019-0578(07)60093-7Seshagiri, R., Rao, V., Chidambaram, M., 2007. Simple Analytical Design of Modified Smith Predictor with Improved Performance for Unstable FirstOrder Plus Time Delay (FOPTD) Processes. Industrial & Engineering Chemistry Research 46 (13), 4561-4571. https://doi.org/10.1021/ie061308nShariati, A., Taghirad, H., Fatehi, A., 2014. A neutral system approach to H PD/PI controller design of processes with uncertain input delay. Journal of Process Control 24 (3), 144-157. https://doi.org/10.1016/j.jprocont.2014.01.003SivaramaKrishnan, S., Tangirla., 2008. Sliding mode controller for unstable systems. Chemical and Biochemical Engineering Quarterly 22 (1), 41-47.Smith, C. A., Corripio, A. B., Basurto, S. D. M., 1991. Control automático de procesos: teoría y práctica. No. 968-18-3791-6. Limusa.Sree, P., Chidambaram, M., 2003a. Control of unstable bioreactor with dominant unstable zero. Chemical and Biochemical Engineering Quarterly 17 (3), 139-145.Sree, P., Chidambaram, M., 2003b. A Simple Method of Tuning PI Controllers for Unstable Systems with a Zero. Chemical and Biochemical EngineeringQuarte rly 17 (3), 207-212.Vilanova, R., Alfaro, V. M., 2011. Control PID robusto: Una visión panorámica. Revista Iberoamericana de Automática e Informática Industrial RIAI 8 (3), 141 - 158. https://doi.org/10.1016/j.riai.2011.06.003Yu, W., Wilson, D., Young, B., 2010. Control performance assessment for nonlinear systems. Journal of Process Control 20 (10), 1235 - 1242. https://doi.org/10.1016/j.jprocont.2010.09.00

Recovery of membrane permeability after filtration of sago starch suspension by tangential flow filtration

Sago starch is extracted from the stems of the sago palm, Metroxylon sagu, in Southeast Asia. A typical Sago starch processing mill in Malaysia generates approximately 20 tons of starch daily containing effluents that can be recovered and marketed to sustain a sm all-scale industry. Tangential flow filtration (TFF) using microfiltration membranes (MFM) has been demonstrated as an effective method for separating suspended solids in biological effluents. When TFF was applied to concentrate the starch from the sago starch suspensions (SSS), the membrane permeability and lifecycle were impacted due to frequent fouling. This study evaluated cleaning methods to recover the permeability and extend the life cycle of MFM following TFF application. Polysulfone membrane filter cassettes of pore size 0.45 μm and surface area 0.1 m2 were each used to separate starch in 100 L of SSS. Following separation, six chemical and physical cleaning methods were tested at laboratory-scale and the degree of cleaning was measured by normalized permeate flux (NPF) and normalized water permeability (NWP). The results showed that soaking the membranes in a 0.2 M NaOH solution (up to 91%, (p<0.05) within a minimum of 72 h, (p<0.05) was the best cleaning method. The procedure has been utilized to maintain and extend the life cycle of the MFM for streams containing starch suspensions

Notable records of amphibians and reptiles from Colima, Nayarit, Jalisco, and Zacatecas, México

[No abstract available

Two new species of Eleutherodactylus (subgenus Syrrhophus) from western Mexico

Reyes-Velasco, Jacobo, Ahumada-Carrillo, Ivan, Burkhardt, Timothy R., Devitt, Thomas J. (2015): Two new species of Eleutherodactylus (subgenus Syrrhophus) from western Mexico. Zootaxa 3914 (3): 301-317, DOI: http://dx.doi.org/10.11646/zootaxa.3914.3.

Notable records of amphibians and reptiles from Colima, Nayarit, Jalisco, and Zacatecas, México

[No abstract available

A facile access to new diazepines derivatives: Spectral characterization and crystal structures of 7-(thiophene-2-yl)-5-(trifluoromethyl)-2,3-dihydro-1H-1,4-diazepine and 2-thiophene-4-trifluoromethyl-1,5-benzodiazepine

International audienceThe one-pot double condensation reaction of 2-thenoyltrifluoroacetone (2-TTA) with ethylendiamine or o-phenylenediamine, in a 2:1 stoichiometric molar ratio, leads to the formation of 7-(thiophene-2-yl)-5-(trifluoromethyl)-2,3-dihydro-1H-1,4-diazepine 2 and 2-thiophene-4-trifluoromethyl-1,5-benzodiazepine 3, that were isolated in 56 and 53% yields, respectively. The bis(trifluoroacetamide)ethylene derivative 1 was also isolated in 32% yield as a side-product in the reaction of 2-TTA and ethylenediamine. Compounds 1–3 were fully characterized by elemental analysis, FT-IR and multinuclear (1H, 13C and 19F) NMR spectroscopy. In addition, their molecular identities and geometries have been authenticated by single-crystal X-ray diffraction analysis. The spectroscopic and structural data confirm that the 1,4-diazepine 2 and the 1,5-benzodiazepine 3 exist in the imine-enamine and diimine tautomeric forms, respectively, both in solution and in the solid-state. © 2016 Elsevier B.V

Tuning of Pareto-optimal robust controllers for multivariable systems. Application on helicopter of two-degress-of-freedom

[ES] La sintonización de controladores Pareto-óptimo robustos ha sido empleada para mejorar el rendimiento de un helicóptero de dos grados de libertad con un algoritmo de control lineal. El procedimiento de sintonización del controlador está basado en la minimización simultánea de las integrales de la suma del cuadrado del error y de la acción de control. Como resultado de dicha minimización y dado que los objetivos entran en conflicto, se obtiene un conjunto de soluciones que describen un frente de Pareto. Posteriormente, un proceso de análisis en los mismos es llevado a cabo para seleccionar los controladores a implementar en el sistema físico. Los resultados experimentales con los controladores seleccionados muestran que el procedimiento de ajuste es eficaz y práctico.[EN] The tuning of Pareto-optimal robust controllers was applied to improve the performance of a helicopter with two-degrees-of-freedom with a linear control algorithm. The tuning procedure is based on the simultaneous minimization of the integral of square sum of errors and the integral of square sum of control action. A 2D Pareto front is built with these integrals. Afterwards, a decision-making process is carried out to select the most preferable controller. Experimental results on the physical platform validate the tuning procedure as practical and reliable.Dirección General de Educación Tecnológica Superior (DGEST), Consejo Nacional de Ciencia y Tecnología (CONACyT), l Ministerio de Economía y Competitividad de España y Consejo Nacional de Desarrollo Científico y Tecnológico de BrasilCarrillo Ahumada, J.; Reynoso Meza, G.; Sanchís Saez, J.; García Nieto, S.; García Alvarado, M. (2015). Sintonización de controladores Pareto-óptimo robustos para sistemas multivariables. Aplicación en un helicóptero de 2 grados de libertad. Revista Iberoamericana de Automática e Informática industrial. 12(2):177-188. https://doi.org/10.1016/j.riai.2015.03.002OJS177188122Carrillo-Ahumada, J., Rodríguez-Jimenes, G. C., & García-Alvarado, M. A. (2011). Tuning optimal-robust linear MIMO controllers of chemical reactors by using Pareto optimality. Chemical Engineering Journal, 174(1), 357-367. doi:10.1016/j.cej.2011.09.007Coello Coello, C. A. (2006). Evolutionary multi-objective optimization: a historical view of the field. IEEE Computational Intelligence Magazine, 1(1), 28-36. doi:10.1109/mci.2006.1597059Corne, D.W., Knowles, J.D., 2007. Techniques for highly multiobjective optimisation: some nondominated points are better than others. En: Proceedings of the 9th annual conference on Genetic and evolutionary computation. GECCO ‘07. ACM, New York, NY, USA, pp. 773-780.CSS, 2012. Unmanned aerial vehicle. special issue. IEEE Control Systems magazine 32 (5).Unmanned Aerial Vehicles and Control: Lockheed Martin Advanced Technology Laboratories. (2012). IEEE Control Systems, 32(5), 32-34. doi:10.1109/mcs.2012.2205474Gabriel, C., 2008. Modelling, simulation and control of a twin rotor mimo-system. Master thesis, Polytechnic University of Valencia, Spain.García-Sanz, M., & Elso, J. (2007). Ampliación del benchmark de diseño de controladores para el cabeceo de un helicóptero. Revista Iberoamericana de Automática e Informática Industrial RIAI, 4(1), 107-110. doi:10.1016/s1697-7912(07)70196-6García-Sanz, M., & Elso, J. (2007). Resultados Del Benchmark de Diseño De Controladores Para el Cabeceo de un Helicóptero. Revista Iberoamericana de Automática e Informática Industrial RIAI, 4(4), 117-120. doi:10.1016/s1697-7912(07)70251-0Garcia-Alvarado, M. A., & Ruiz-López, I. I. (2010). A design method for robust and quadratic optimal MIMO linear controllers. Chemical Engineering Science, 65(11), 3431-3438. doi:10.1016/j.ces.2010.02.033Hernández, L. H., Pestana, J., Palomeque, D. C., Campoy, P., & Sanchez-Lopez, J. L. (2013). Identificación y control en cascada mediante inversión de no linealidades del cuatrirrotor para el Concurso de Ingeniería de Control CEA IFAC 2012. Revista Iberoamericana de Automática e Informática Industrial RIAI, 10(3), 356-367. doi:10.1016/j.riai.2013.05.008Huba, M. (2013). Performance measures, performance limits and optimal PI control for the IPDT plant. Journal of Process Control, 23(4), 500-515. doi:10.1016/j.jprocont.2013.01.002Ishibuchi, H., Tsukamoto, N., Nojima, Y., 2008. Evolutionary many-objective optimization: A short review. En: Evolutionary Computation, 2008. CEC 2008. (IEEE World Congress on Computational Intelligence). IEEE Congress on.Juang, J.-G., Lin, R.-W., & Liu, W.-K. (2008). Comparison of classical control and intelligent control for a MIMO system. Applied Mathematics and Computation, 205(2), 778-791. doi:10.1016/j.amc.2008.05.061Juang, J.-G., Liu, W.-K., & Lin, R.-W. (2011). A hybrid intelligent controller for a twin rotor MIMO system and its hardware implementation. ISA Transactions, 50(4), 609-619. doi:10.1016/j.isatra.2011.06.006Lotov, A., Miettinen, K., 2008. Visualizing the Pareto frontier. In: Branke, J., Deb, K., Miettinen, K., Slowinski, R. (Eds.), Multiobjective Optimization. Vol. 5252 of Lecture Notes in Computer Science. Springer Berlin /Heidel-berg, pp. 213-243.Marler, R. T., & Arora, J. S. (2004). Survey of multi-objective optimization methods for engineering. Structural and Multidisciplinary Optimization, 26(6), 369-395. doi:10.1007/s00158-003-0368-6Rahideh, A., Shaheed, M., april 2009. Robust model predictive control of a twin rotor mimo system. En: Mechatronics, 2009. ICM 2009. IEEE International Conference on. pp. 1-6.Rahideh, A., & Shaheed, M. H. (2012). Constrained output feedback model predictive control for nonlinear systems. Control Engineering Practice, 20(4), 431-443. doi:10.1016/j.conengprac.2011.12.003Reynoso-Meza, G., Sanchis, J., Blasco, X., Herrero, J.M., August 2014a. A stabilizing PID controller sampling procedure for stochastic optimizers. En: Memories of the 19th World Congress IFAC 2014. pp. 8158-8163.Reynoso-Meza, G., Blasco, X., Sanchis, J., & Martínez, M. (2014). Controller tuning using evolutionary multi-objective optimisation: Current trends and applications. Control Engineering Practice, 28, 58-73. doi:10.1016/j.conengprac.2014.03.003Reynoso-Meza, G., Sánchez, H.S., Blasco, X., Vilanova, R., August 2014c. Reliability based multiobjective optimization design procedure for PI controller tuning. En: Memories of the 19th World Congress IFAC 2014. pp. 10263-10268.Ruiz-López, I. I., Rodríguez-Jimenes, G. C., & García-Alvarado, M. A. (2006). Robust MIMO PID controllers tuning based on complex/real ratio of the characteristic matrix eigenvalues. Chemical Engineering Science, 61(13), 4332-4340. doi:10.1016/j.ces.2006.02.015Skogestad, S. (2003). Simple analytic rules for model reduction and PID controller tuning. Journal of Process Control, 13(4), 291-309. doi:10.1016/s0959-1524(02)00062-8Sánchez, H.S., Vilanova, R., 2013a. Multiobjective tuning of PI controller using the NNC method: Simplified problem definition and guidelines for decision making. En: Proceedings of the 18th. IEEE Conference on emerging technologies & factory automation (ETFA).Sánchez, H.S., Vilanova, R., 2013b. Nash-based criteria for selection of pareto optimal controller. En: Proceedings of the 17th. International Conference on System Theory, Control anmd Computing.Tao, C. W., Taur, J. S., & Chen, Y. C. (2010). Design of a parallel distributed fuzzy LQR controller for the twin rotor multi-input multi-output system. Fuzzy Sets and Systems, 161(15), 2081-2103. doi:10.1016/j.fss.2009.12.007Tao, C.-W., Taur, J.-S., Chang, Y.-H., & Chang, C.-W. (2010). A Novel Fuzzy-Sliding and Fuzzy-Integral-Sliding Controller for the Twin-Rotor Multi-Input&#x2013;Multi-Output System. IEEE Transactions on Fuzzy Systems, 18(5), 893-905. doi:10.1109/tfuzz.2010.2051447Toha, S., Tokhi, M., nov. 2009. Dynamic nonlinear inverse-model based control of a twin rotor system using adaptive neuro-fuzzy inference system. En: Computer Modeling and Simulation, 2009. EMS ‘09. Third UKSim European Symposium on. pp. 107-111.Vargas, F. J., Salgado, M. E., & Silva, E. I. (2011). Optimal ripple-free deadbeat control using an integral of time squared error (ITSE) index. Automatica, 47(9), 2134-2137. doi:10.1016/j.automatica.2011.06.006Velasco, J., García-Nieto, S., Reynoso-Meza, G., Sanchis, J., 2013. Implementación de un sistema hardware-in-the-loop para la simulación en tiempo real de pilotos automáticos para uavs. En: de Automática, C.E. (Ed.), Memorias de las XXXIV Jornadas de Automática.Vilanova, R., Alfaro, V. M., & Arrieta, O. (2012). Simple robust autotuning rules for 2-DoF PI controllers. ISA Transactions, 51(1), 30-41. doi:10.1016/j.isatra.2011.09.001Wen, P., & Lu, T.-W. (2008). Decoupling control of a twin rotor MIMO system using robust deadbeat control technique. IET Control Theory & Applications, 2(11), 999-1007. doi:10.1049/iet-cta:20070335Witczak, M., Puig, V., de Oca, S., oct. 2010. A fault-tolerant control scheme for non-linear discrete-time systems: Application to the twin-rotor system. En: Control and Fault-Tolerant Systems (SysTol), 2010 Conference on. pp. 861-866

Octahedral bis(2-thenoyltrifluoroacetonato)-ethylenediamine Co(II), Ni(II) and Cu(II) complexes: Synthetic, structural, electrochemical, and theoretical studies

International audienceWe report the synthesis of three new octahedral bis(2-thenoyltrifluoroacetonato)-ethylenediamine metal(II) complexes [M(TTA)2(en)] (M = Co, 2a; Ni, 2b; Cu, 2c) resulting from the coordination of the diamine onto the bis(β-diketonate) precursors [Co(TTA)2(CH3OH)2] (1a), [Ni(TTA)2(H2O)2] (1b) and [Cu(TTA)2] (1c), respectively. The six-coordinate paramagnetic complexes 2a-c have been isolated as neutral, air and thermally stable solids in high yields (andgt;80%) and have been fully characterized by elemental analysis, ESI+ HRMS, FT-IR and UV–vis spectroscopy. Single-crystal X-ray diffraction studies indicate that the metal(II) ion sits in a pseudo-octahedral environment; the copper derivative 2c showing a significant elongation along the O–Cu–O axis due to Jahn-Teller distorsion associated with the “eg” electron occupation of the dz2-type MO. The three complexes 2a-c display similar cyclic voltammetric behavior exhibiting two irreversible anodic waves, tentatively assigned to the M(II)/M(III) redox couples and to the oxidation of soluble short oligomeric species generated during the first redox process, respectively. No deposits of polymeric species on the electrode surface occured. The electronic structures of 2a-c and their cations have been analysed through DFT calculations, allowing providing a consistent view of their structure and properties. TDDFT calculations have been used to interpret the major features of their UV–vis spectra. © 2017 Elsevier B.V

Spectroscopic, structural, electrochemical and computational studies of some new 2-thienyl-containing β-diketonate complexes of cobalt(II), nickel(II) and copper(II)

International audienceIn this work, we present the synthesis of the unsymmetrical β-diketone 1-(2-thienyl)-3-(4-fluorophenyl)-propane-1,3-dione (HL) and its corresponding Co(II), Ni(II) and Cu(II) bis(β-diketonato) complexes 1–3, respectively. The four new compounds were isolated in good yields (65–70%), and characterized by mass spectrometry, elemental analysis, FT-IR and UV–Vis spectroscopy and, in the case of HL, by 1H, 13C and 19F NMR spectroscopy. In addition, the molecular identities and the geometries of the β-diketone HL and complex 3 were confirmed by X-ray diffraction analysis. The dicarbonyl derivative HL does exist as the diketo tautomeric form in DMSO solution and as its keto-enol tautomer in the solid-state with the –OH group adjacent to the 4-fluorophenyl unit. The keto-enol isomer was computed to be more stable by 8.2 kcal/mol in free energy at room temperature. In 3, the Cu(II) center adopts a perfect square-planar geometry. Two reduction processes were observed in the cyclovoltammogram of 3 at −1.30 and −1.80 V vs. Fc/Fc+, with copper deposit on the surface of the electrode. DFT and TD-DFT calculations on HL and complex 3 allow rationalizing their stability, bonding and properties. © 2017 Elsevier B.V

Novel Co(II), Ni(II) and Cu(II) complexes involving a 2-thienyl and trifluoromethyl containing symmetrically-substituted tetradentate Schiff-base ligand Syntheses, structures, electrochemical and computational studies

International audienceHere, we report three novel metal(II) complexes (M = Co, 3a; Ni, 3b; Cu, 3c) involving a symmetrically-substituted N2O2-tetradentate Schiff base ligand bearing trifluoromethyl and 2-thienyl substituents. Complexes 3a–c were readily synthesized upon reaction of the diprotic Schiff base proligand with the appropriate hydrated metal(II) acetates, and isolated as neutral, air and thermally stable solids in good to excellent yields (andgt;65–85%). All the complexes have been well characterized using elemental analysis and different spectroscopic tools (ESI+ HRMS, FT-IR, UV–Vis), and single crystal X-ray diffraction analysis for 3b and 3c. Their crystal structures revealed a four-coordinate square planar geometry at the Ni(II) and Cu(II) metal ions, with two nitrogen and two oxygen atoms as donors. Complexes 3a–c displayed similar cyclic voltammetric behavior, exhibiting one anodic and one cathodic wave, both irreversible and of different intensity. They were tentatively assigned to M(II)/M(III) and M(II)/M(I) redox couples, respectively. No deposits of polymeric films on the electrode surface were observed. Structural, electrochemical and electronic parameters of the complexes have been rationalized on the ground of DFT and TD-DFT computation