Predictor-Feedback Stabilization of Multi-Input Nonlinear Systems

We develop a predictor-feedback control design for multi-input nonlinear systems with distinct input delays, of arbitrary length, in each individual input channel. Due to the fact that different input signals reach the plant at different time instants, the key design challenge, which we resolve, is the construction of the predictors of the plant's state over distinct prediction horizons such that the corresponding input delays are compensated. Global asymptotic stability of the closed-loop system is established by utilizing arguments based on Lyapunov functionals or estimates on solutions. We specialize our methodology to linear systems for which the predictor-feedback control laws are available explicitly and for which global exponential stability is achievable. A detailed example is provided dealing with the stabilization of the nonholonomic unicycle, subject to two different input delays affecting the speed and turning rate, for the illustration of our methodology.Comment: Submitted to IEEE Transactions on Automatic Control on May 19 201

Neural Network Based Central Heating System Load Prediction and Constrained Control

A neural network (NN) based heating system load prediction and control scheme are proposed. Different from traditional physical principle based load calculation method, a multilayer NN is incorporated with selected input features and trained to predict the heating load as well as the desired supply water temperature in heating supply loop. In this manner, a complicated load calculation model can be replaced by simple but efficient data-driven scheme and the response time to outdoor temperature variation can be enhanced. Moreover, in order to handle the input and output constraints in valve opening degree control task to achieve desired supply water temperature, Barrier Lyapunov candidate function and axillary system technique are involved. An additional NN is employed to approximate the system transfer function with reliable accuracy. The stability of the system is guaranteed through rigorous mathematical analysis. The excellent performance of the novelly proposed control over traditional PID is demonstrated via extensive simulation study. A quantitative case study is also conducted to verify the flexibility and validity of proposed load prediction strategy

Trajectory tracking of a mobile robot (3,0) by means of bounded control

[EN] The present work deals with the tracking problem of a mobile robot (3,0) based on the kinematic model and proposes a control strategy that takes into account a priori input signals bounds i.e. the linear and angular velocity of the robot. The objective of this control approach is to maximize the effectiveness of the actuators without taking a risk in the system stability. The resulting nonlinear control is composed of a nonlinear compensator based on the kinematic model and nested saturation approach. The control law can be tuned to force the error dynamics trajectories to enter in a neighborhood of the origin in a finite time and remain thereafter. Experimental results show the performance of the closed loop system. Furthermore, owing to simplicity, the proposed control law is suitable for application where on-board computational resources are limited.[ES] El presente trabajo aborda el problema de seguimiento de trayectoria para el robot (3, 0) basado en su modelo cinemático y propone una solución mediante el diseño de una estrategia de control que a priori toma en cuenta las cotas máximas permitidas de la señal de control i.e. la velocidad lineal y angular máximas que puede alcanzar el robot móvil. El objetivo es maximizar el uso de los actuadores sin poner en riesgo la estabilidad del sistema. La ley de control no lineal resultante se compone de un compensador no lineal basado en el modelo cinemático y de funciones de saturación anidadas. Esta ley de control contiene parámetros de sintonización que permiten que las trayectorias de la dinámica del error ingresen a una vecindad del origen, en un tiempo finito y se mantengan de ah́ı en adelante. Resultados experimentales sustentan los resultados teóricos, muestran el desempeño del sistema de control en lazo cerrado y lo comparan con una estrategia que no toma en cuenta los ĺımites de la señal de control. Debido a su simplicidad, la estrategia de control propuesta permite ser implementada en sistemas embebidos con bajo coste computacional.El primer autor agradece a la Vicerrectoría de Investigación y Estudios de Posgrado de la BUAP por el apoyo brindado en esta investigación bajo el proyecto GUCJING14-I. El segundo autor agradece el apoyo de la Comisión de Operación y Fomento de Actividades Académicas (COFAA) y a la Secretaría de Investigación y Posgrado (SIP) del Instituto Politécnico Nacional bajo los proyectos No. 20131053, 20140926 y al CONACYT bajo el apoyo 182298. El tercer autor agradece el apoyo brindado por Facultad de Ciencias de la Electrónica de la BUAP y a la UPPUE por el otorgamiento del ano sabático que permitió la culminación del presente trabajo. El cuarto autor agradece al CONACYT por la beca de estudios de maestría.Guerrero Castellanos, J.; Villarreal Cervantes, M.; Sánchez Santana, J.; Ramírez Martínez, S. (2014). Seguimiento de trayectorias de un robot móvil (3,0) mediante control acotado. Revista Iberoamericana de Automática e Informática industrial. 11(4):426-434. https://doi.org/10.1016/j.riai.2014.09.005OJS426434114Araújo, A., Portugal, D., Couceiro, M. S., Sales, J., & Rocha, R. P. (2014). Desarrollo de un robot móvil compacto integrado en el middleware ROS. Revista Iberoamericana de Automática e Informática Industrial RIAI, 11(3), 315-326. doi:10.1016/j.riai.2014.02.009Arfiadi, Y., & Hadi, M. N. S. (2006). Continuous bounded controllers for active control of structures. Computers & Structures, 84(12), 798-807. doi:10.1016/j.compstruc.2006.01.001Gutierrez Arias, J. E. M., Hernández Angulo, L., Morín Castillo, M. M., & Flores Mena, J. E. (2011). Control Óptimo para Trayectorias Circulares en un Robot Móvil. Revista Iberoamericana de Automática e Informática Industrial RIAI, 8(3), 229-240. doi:10.1016/j.riai.2011.06.010Aström, K., Murray, R., 2010. Feedback Systems: An Introduction for Scientists and Engineers. Princeton University Press. URL http://books.google.com.mx/books?id=cdG9fNqTDS8C.Cañas, N., Hernández, W., González, G., & Sergiyenko, O. (2014). Controladores multivariables para un vehículo autónomo terrestre: Comparación basada en la fiabilidad del software. Revista Iberoamericana de Automática e Informática Industrial RIAI, 11(2), 179-190. doi:10.1016/j.riai.2014.02.002Campion, G., Bastin, G., & Dandrea-Novel, B. (1996). Structural properties and classification of kinematic and dynamic models of wheeled mobile robots. IEEE Transactions on Robotics and Automation, 12(1), 47-62. doi:10.1109/70.481750Chaos, D., Moreno-Salinas, D., Muñoz, R., & Aranda, J. (2013). Control no lineal de un aerodeslizador no holonómico con acciones de control limitadas. Revista Iberoamericana de Automática e Informática Industrial RIAI, 10(4), 402-412. doi:10.1016/j.riai.2013.05.012Fischer, N., Dani, A., Sharma, N., & Dixon, W. E. (2013). Saturated control of an uncertain nonlinear system with input delay. Automatica, 49(6), 1741-1747. doi:10.1016/j.automatica.2013.02.013Guerrero-Castellanos, J. F., Marchand, N., Hably, A., Lesecq, S., & Delamare, J. (2011). Bounded attitude control of rigid bodies: Real-time experimentation to a quadrotor mini-helicopter. Control Engineering Practice, 19(8), 790-797. doi:10.1016/j.conengprac.2011.04.004Guerrero-Castellanos, J. F., Téllez-Guzmán, J. J., Durand, S., Marchand, N., Alvarez-Muñoz, J. U., & González-Díaz, V. R. (2013). Attitude Stabilization of a Quadrotor by Means of Event-Triggered Nonlinear Control. Journal of Intelligent & Robotic Systems, 73(1-4), 123-135. doi:10.1007/s10846-013-9890-yKaliora, G., & Astolfi, A. (2005). On the stabilization of feedforward systems with bounded control. Systems & Control Letters, 54(3), 263-270. doi:10.1016/j.sysconle.2004.08.011Marchand, N., & Hably, A. (2005). Global stabilization of multiple integrators with bounded controls. Automatica, 41(12), 2147-2152. doi:10.1016/j.automatica.2005.07.004Rifaï, H., Marchand, N., & Poulin-Vittrant, G. (2012). Bounded control of an underactuated biomimetic aerial vehicle—Validation with robustness tests. Robotics and Autonomous Systems, 60(9), 1165-1178. doi:10.1016/j.robot.2012.05.011Sussmann, H. J., Sontag, E. D., & Yang, Y. (1994). A general result on the stabilization of linear systems using bounded controls. IEEE Transactions on Automatic Control, 39(12), 2411-2425. doi:10.1109/9.362853Teel, A. R. (1992). Global stabilization and restricted tracking for multiple integrators with bounded controls. Systems & Control Letters, 18(3), 165-171. doi:10.1016/0167-6911(92)90001-