This paper depicts a self-tuning adaptive control method along with a novel robust procedure to system identification which is applied to a single-phase full-bridge Inverter with LC filter by Pulse Width Modulation (P...
详细信息
This paper depicts a self-tuning adaptive control method along with a novel robust procedure to system identification which is applied to a single-phase full-bridge Inverter with LC filter by Pulse Width Modulation (PWM). Moreover, an LC filter is designed to decrease the disturbing harmonics produced by PWM which, the stability of the filter can be noted as an important issue. On the other hand, a dynamic change of the inverter can lead to instability issues in which the proposed approach can overcome this problem and perform with a great response. Due to the parametric uncertainty on a full-bridge inverter and other disturbing factors, a digital adaptive controller is proposed which is performed by minimum degree pole placement (MDPP) technique combined with Improved Exponential Regressive Least identification (IERLS) algorithm. To prevent the undesired influences of high variance noises and disturbance on the performance of the identification approach, a robust identification algorithm is introduced which is capable of keeping the parametric estimation process in a desired range. Additionally, to deal with the variations of supply DC voltage, a proportional-integral-derivative (PID) controller is designed. Finally, the experimental and simulation results are performed by Matlab-Simulink to show the validation of the work.
A novel on-line auto-tuning PI control algorithm for the superheat of the evaporator is proposed in this paper. A first-order plus dead-time model is firstly employed to describe the system process, and the model para...
详细信息
ISBN:
(纸本)9781538635247
A novel on-line auto-tuning PI control algorithm for the superheat of the evaporator is proposed in this paper. A first-order plus dead-time model is firstly employed to describe the system process, and the model parameters are obtained from the robust identification algorithm using the on-line experimental data. Then, a PI controller, whose parameters are tuned by the Ziegler-Nichols method, is designed to control the superheat at the outlet of evaporator by adjusting the opening of the electronic expansion valve. The MATIAB simulation results show the superheat can well track the change of its setting point through the effective control of the electronic expansion valve. The wide application of this controller will greatly increase the heat transfer efficiency of the evaporator.
Intensive research in the field of mathematical modeling of pneumatic servo drives has shown that their mathematical models are nonlinear in which many important details cannot be included in the model. Owing the infl...
详细信息
Intensive research in the field of mathematical modeling of pneumatic servo drives has shown that their mathematical models are nonlinear in which many important details cannot be included in the model. Owing the influence of the combination of heat coefficient, unknown discharge coefficient, and change of temperature, it was supposed that parameters of the pneumatic cylinder are random (stochastic parameters). On the other side, it has been well known that the nonlinear model can be approximated by a linear model with time-varying parameters. Due to the aforementioned reasons, it can be assumed that the pneumatic cylinder model is a linear stochastic model with variable parameters. In practical conditions, in measurements, there are rare, inconsistent observations with the largest part of population of observations (outliers). Therefore, synthesis of robustalgorithms is of primary interest. In this paper, the robust recursive algorithm for output error models with time-varying parameters is proposed. The convergence property of the proposed robustalgorithm is analyzed using the methodology of an associated ordinary differential equation system. Because ad hoc selection of model orders leads to overparameterization or parsimony problem, the robust Akaike's criterion is proposed to overcome these problems. By determining the least favorable probability density for a given class of probability distribution represents a base for design of the robust version of Akaike's criterion. The behavior of the proposed robust identification algorithm is considered through intensive simulations that demonstrate the superiority of the robustalgorithm in relation to the linear algorithms (derived under an assumption that the stochastic disturbance has a Gaussian distribution). The good practical values of the proposed robustalgorithm to identification of the pneumatic cylinder are illustrated by experimental results. Copyright (c) 2016 John Wiley & Sons, Ltd.
The problem of constructing non-asymptotic (true from the first step) estimates of the convergence rate of robustidentification on-line algorithms is considered. Estimates which are correct at each procedural step wi...
详细信息
The problem of constructing non-asymptotic (true from the first step) estimates of the convergence rate of robustidentification on-line algorithms is considered. Estimates which are correct at each procedural step with any preassigned probability are shown for the one-dimensional algorithm class. Examples of such estimates are given.
暂无评论