In this paper, a recurrent high order neural observer (RHONO) for anaerobic processes is proposed. The main objective is to estimate variables of methanogenesis: biomass, substrate and inorganic carbon in a completely stirred tank reactor (CSTR). The recurrent high order neural network (RHONN) structure is based on the hyperbolic tangent as activation function. The learning algorithm is based o...

This paper deals with a class of chemical process with measurable time-varying disturbances, which is modeled within the framework of singular perturbation in non-standard form. The results in singular perturbation theory consider the systems in a standard form, therefore, a transformation to change a system representation from non-standard to standard form should be found. After this transform...

This article describes the use of biofilm reactors for the production of various chemicals by fermentation and wastewater treatment. Biofilm formation is a natural process where microbial cells attach to the support (adsorbent) or form flocs/aggregates (also called granules) without use of chemicals and form thick layers of cells known as "biofilms." As a result of biofilm formation, cell densi...

In this paper, a regulation control problem for constrained nonlinear systems with quantized inputs is formulated as a Model Predictive Control (MPC) problem. The MPC problem is represented as a multi-parametric Nonlinear Integer Programming (mp-NIP) problem and a computational method to find an explicit approximate solution of this problem is considered. It consists in constructing a feasible ...

The paper focuses on the application of neural network techniques in fault detection and diagnosis. The objective of this paper is to detect and diagnose the faults to a continuous stirred tank reactor (CSTR). Fault detection is performed by using the error signals, where when error signal is zero or nearly zero, the system is in normal condition, and when the fault occurs, error signals should...

This paper presents a numerical analysis for complex 3D simulations of the Stirred Tank Reactor (STR) model by a modified discrete projection method (DPM) for rotating incompressible flow. For several prototypical configurations of the STR model, we examine the multigrid behaviour for the arising momentum and pressure Poisson subproblems for different values of the time step, the angular veloci...

Nonlinear Model Predictive Control (NMPC) has gained wide attention through the application of dynamic optimization. However, this approach is susceptible to computational delay, especially if the optimization problem cannot be solved within one sampling time. In this paper we propose an advanced-multi-step NMPC (amsNMPC) method based on nonlinear programming (NLP) and NLP sensitivity. This met...

Qualitative modeling of technical processes may be accomplished by dynamic fuzzy systems. A new inference method with interpolating rules is proposed as an essential basis for the analysis of this class of systems. Using this approach, the system output is dependent on both an interpolating rule derived from the fuzzy input and the fuzzy input itself. A simple example shows the typical behavior...

The concept of control Lyapunov functions (CLF) has recently been extended to time delay system in the form of control Lyapunov-Razumikhin functions (CLRF) and control Lyapunov-Krasovsky functionals (CLKF). If a CLKF is known for a nonlinear time delay system, several stabilizing control laws can be constructed using one of the universal formulas derived for CLF’s. In this paper we establish a ...

This work addresses the design and performance evaluation of a control system for a class of continuous stirred tank reactors to produce homopolymers via free radicals. The control system claims to be of practical implementation in the sense that: (i) it manages both measurement types existing in this class of processes: continuous-instantaneous, and discrete-delayed with a periodic sampling-ti...