Subdiffusive Source Sensing by a Regional Detection Method.

Motivated by the fact that the danger may increase if the source of pollution problem remains unknown, in this paper, we study the source sensing problem for subdiffusion processes governed by time fractional diffusion systems based on a limited number of sensor measurements. For this, we first give some preliminary notions such as source, detection and regional spy sensors, etc. Secondly, we investigate the characterizations of regional strategic sensors and regional spy sensors. A regional detection approach on how to solve the source sensing problem of the considered system is then presented by using the Hilbert uniqueness method (HUM). This is to identify the unknown source only in a subregion of the whole domain, which is easier to be implemented and could save a lot of energy resources. Numerical examples are finally included to test our results

Fractional-order PID control strategy on hydraulic-loading system of typical electromechanical platform

In this paper, a control method for a hydraulic loading system of an electromechanical platform based on a fractional-order PID (Proportion-Integration-Differentiation) controller is proposed, which is used to drive the loading system of a mechatronic journal test rig. The mathematical model of the control system is established according to the principle of the electro-hydraulic system. Considering the indetermination of model parameters, the method of parameter identification was used to verify the rationality of the theoretical model. In order to improve the control precision of the hydraulic loading system, the traditional PID controller and fractional-order PID controller are designed by selecting appropriate tuning parameters. Their control performances are analyzed in frequency domain and time domain, respectively. The results show that the fractional-order PID controller has better control effect. By observing the actual control effect of the fractional-order PID controller on the journal test rig, the effectiveness of this control algorithm is verified

Fractional-Order PID Control Strategy on Hydraulic-Loading System of Typical Electromechanical Platform

In this paper, a control method for a hydraulic loading system of an electromechanical platform based on a fractional-order PID (Proportion-Integration-Differentiation) controller is proposed, which is used to drive the loading system of a mechatronic journal test rig. The mathematical model of the control system is established according to the principle of the electro-hydraulic system. Considering the indetermination of model parameters, the method of parameter identification was used to verify the rationality of the theoretical model. In order to improve the control precision of the hydraulic loading system, the traditional PID controller and fractional-order PID controller are designed by selecting appropriate tuning parameters. Their control performances are analyzed in frequency domain and time domain, respectively. The results show that the fractional-order PID controller has better control effect. By observing the actual control effect of the fractional-order PID controller on the journal test rig, the effectiveness of this control algorithm is verified

Evaluación y análisis comparativo de las estrategias de sintonización, optimización y aproximación de controladores de orden fraccionario aplicados a sistemas mecatrónicos.

Se realizó una evaluación comparativa del desempeño de los diferentes controladores PID de orden fraccionario (FOPID) aplicados a procesos FODPT, el proceso utilizado en este estudio es un motor DC. En el procedimiento de diseño de los controladores FOPID se utilizan cuatro etapas: métodos de sintonización, algoritmos de optimización, índices de desempeño y algoritmos de aproximación. En cada una de estas etapas existe una variedad de metodologías y algoritmos, lo cual vuelve complejo el diseño de un controlador FOPID aplicado a un proceso en particular. Para el análisis comparativo se utilizó cuatro(4 )métodos de sintonización: Ziegler-Nichols, Amstrom-Hagglund (AMIGO) , Chien-Hromes-Reswick (CHR)y Cohen Coon ( CC); además se aplicó (3)algoritmos de optimización Nelder-Mead (NM) , el punto interior (IP) y el algoritmo secuencial de programación cuadrática (SQP ); con respecto a la fase de aproximación de orden fraccional a orden entero, se utilizo tres (3) algoritmos: Crone,Matsuday Carlson; y finalmente para cuantificar el desempeño de, método de sintonización e utilizaron cuatro (4) índices de error: ISE,IAE,ITSE e ITAE. Como resultado del presente trabajo se generaron 180 controladores FOPID, de los cuales se muestra que, al aplicar el algoritmo de sintonización de ZN, junto con el algoritmo de optimización SQP, seleccionando la métrica de desempeño ITAE y el algoritmo de aproximación Matsuda, se convierte en la comunicación optima de estrategias aplicadas al diseño de controladores FOPID. La simulación en lazo cerrado entre este controlador y el proceso nos entregó los mejores resultados en la respuesta temporal, se obtuvo un porcentaje de sobre elongación de 1.07% y un tiempo de establecimiento de 1.3 milisegundos. Finalmente, se recomienda emplear la planta identificada por la herramienta PID Tuner, este modelo de primer orden con tiempo de retardo presenta mejores resultados de simulación en los parámetros temporales con respecto a los otros modelos.A comparative evaluation of the performance of the different fractional order PID controllers (FOPID) applied to FODPT processes was performed, the process used in this study is a DC motor. Four steps are used in the design procedure of FOPID controllers: tuning methods, optimization algorithms, performance indexes and approximation algorithms. In each of these stages there is a variety of methodologies and algorithms, which makes the design of a FOPID controller applied to a particular process complex. For the comparative analysis four (4) tuning methods were used: Ziegler-Nichols, Amstrom-Hagglund (AMIGO), Chien-Hromes-Reswick (CHR) and Cohen Coon (CC); In addition, (3) Nelder-Mead optimization algorithms (NM), the internal point (IP) and the sequential quadratic programming algorithm (SQP) were applied; With respect to the phase of approximation of fractional order to whole order, three (3) algorithms were used: Crone, Matsuday Carlson; and finally to quantify the performance of the tuning method and used four (4) error rates: ISE, IAE, ITSE and ITAE. As a result of this work, 180 FOPID controllers were generated, of which it is shown that, when applying the ZN tuning algorithm, together with the SQP optimization algorithm, selecting the ITAE performance metric and the Matsuda approximation algorithm, it becomes in the optimal communication of strategies applied to the design of FOPID controllers. The closed loop simulation between this controller and the process gave us the best results in the temporal response, an elongation percentage of 1.07% was obtained and an establishment time of 1.3 milliseconds. Finally, it is recommended to use the plant identified by the PID Tuner tool, this first-order model with delay time has better simulation results in the temporal parameters with respect to the other models