Antonio S. Silveira

Robust design of a 2-DOF GMV controller: a direct self-tuning and fuzzy scheduling approach.

This paper presents a study on self-tuning control strategies with generalized minimum variance control in a fixed two degree of freedom structure-or simply GMV2DOF-within two adaptive perspectives. One, from the process model point of view, using a recursive least squares estimator algorithm for direct self-tuning design, and another, using a Mamdani fuzzy GMV2DOF parameters scheduling technique based on analytical and physical interpretations from robustness analysis of the system. Both strategies are assessed by simulation and real plants experimentation environments composed of a damped pendulum and an under development wind tunnel from the Department of Automation and Systems of the Federal University of Santa Catarina.

Model-free adaptive PID controllers applied to the benchmark PID'12

Abstract Many tuning strategies for PID control algorithms have been proposed in the literature depending on modeling choice from heuristics, physical laws and/or experimental essays. In this paper, the properties of three model-free adaptive PID control design conceptions, known as direct PID control, are investigated and implemented. The recursive least squares estimator is used to identify the PID controller gains without the knowledge of the plant mathematical model. The tuning strategies of the direct PID controller are applied to the boiler control system proposed by Fernando Morilla (UNED, Spain) as a benchmark problem for the 2012 IFAC Conference on Advances in PID Controllers.

Aplicação da sintonia IMC no controlador PID em sistemas não-lineares simulados com ScicosLab

In the process industry the loop problem is how to choose a suitable set of PID parameters because of their influence on the asymptotic stability of the system. This paper develops a PID control algorithm based on Internal Model Control (IMC) design for linear and nonlinear control systems in the discrete-time domain under satisfactory performance. Compared with traditional feedback controllers, IMC can indicate the relationship between tuning parameters to the closed-loop dynamic and robustness and guaranteed control performance. Validation results against linear and nonlinear physical plant models are convincing, with excellent closed-loop responses and good robustness in the presence of practical constraints, time-varying parameters and disturbances.

Low Cost Setup to Support PID Ideas in Control Engineering Education

Abstract A laboratory equipment that has been employed in experimental activities to code real-time PID control algorithms is described in this paper. This digital apparatus, including a MTG plant (motor+tachometer) and a simple data acquisition board, is flexible to assess not only PID controller loop methodologies but also tuning and design aspects. Among the different possibilities of using a PID control algorithm, the students can realize and be in touch with their own control code implementation. These essays raise, a bit more, the motivation for PID control lessons. In particular, the whole real-time equipment operates in the industrial pattern of voltage, is cheap and is easy to install as standard control equipment in any control laboratory. The main advantage is the very low cost if compared to similar laboratory scale educational setup. Three control tasks for the students in a discipline called Feedback Systems are taken as examples and evaluation results from the students are shown.

GMV-PID controller design with gradient method for the energy weighting factor in nonlinear plants

Abstract Since the PID tuning formula of Ziegler-Nichols step test, perhaps the best known, the process control literature is still showing lots of PID control schemes to improve the closed-loop stability. In this paper, using the relationship between the PID and generalized minimum variance (GMV) controller and adjusting online the control weighting factor by an adaptive learning algorithm of first-order (gradient method), a new control design is investigated. Besides, the control algorithm is gathering the direct estimation technique, with the covariance resetting procedure based on the weighted prediction error, to deal with nonlinear plants. Numerical and practical experiments are shown to evaluate the behavior of the proposed GMV-PID control design.

Pseudo-PID Controller: Design, Tuning and Applications

Abstract In this paper, a pseudo PID (PPID) controller, including only one gain to be tuned, is proposed. The idea is to connect the I+PD control design with the Fertik and Ziegler-Nichols tuning rules in order to obtain not only a simple and efficient control algorithm but also to decrease the operator intervention time with respect to the calibration task and to obtain desired closed-loop dynamic. Three approaches for stable automatic tuning via, self-tuning, internal model control and small gain theorem, are investigated for adjusting the tuning parameter of the controller. Effectiveness and performance aspects of the proposed PPID controller are assessed in numerical and experimental plants.

Teaching PID Tuning with IMC Design for Dynamic Systems using ScicosLab

Abstract In industrial processes a control loop problem is how to choose a suitable set of PID parameters because of their influence on the system asymptotic stability. This paper aims to show the advantages of using Free Open Source Software in control education. A PID control algorithm based on Internal Model Control design for linear plants, in the discrete-time domain, is derived. Some examples for simulating typical control systems and a real-time physical plant are given to explore not only the controller tuning, closed-loop dynamics, robustness in the presence of practical constraints, time-varying parameters and disturbances, but also the strategy by using ScicosLab as a suitable free software tool to be used for learning in process control and to integrate with the data acquisition board MCC 1208LS.

Avaliação e projeto de um controlador self-tuning na estabilização de sistemas oscilatórios

This paper describes the development and a real application of a new digital self-tuning control scheme when applied to a damped pendulum system for trajectory tracking. The proposed control technique is derived from the optimization of a quadratic performance index which includes an additional weighted derivative term. The self-tuning control action is implemented with a recursive identification procedure with a covariance matrix reset scheme in order to find good process parameters. Experimental simulations show that the self-tuning controller provides a significant improvement in the system behavior, with setpoint tracking and increasing the damping of oscillations in the system over a range of operating conditions.