Ruben Rojas - Academia.edu (original) (raw)

Papers by Ruben Rojas

Research paper thumbnail of Multivariate statistical analysis to detect insulin infusion set failure

Multivariate statistical analysis techniques are applied to insulin infusion set failure detectio... more Multivariate statistical analysis techniques are applied to insulin infusion set failure detection (IISF), a challenging problem faced by individuals with type 1 diabetes that are on continuous insulin infusion pump therapy. Bivariate classification (BC), principal component analysis (PCA), and a combined approach were applied to simulated glucose concentrations for 10 patients, based on a nonlinear physiological model of insulin and glucose dynamics. The PCA algorithm had fewer false alarms than BC, while detecting most drifting (ramp) infusion set failures before complete failure occurred.

Research paper thumbnail of A General Sliding Mode Controller for Nonlinear Chemical Processes

Journal of Dynamic Systems Measurement and Control-transactions of The Asme, 2000

... Sira-Ramirez, H., and Llanes-Santiago, O., 1994, “Dynamical Discontinuous Feedback Strategies... more ... Sira-Ramirez, H., and Llanes-Santiago, O., 1994, “Dynamical Discontinuous Feedback Strategies In The Regulation of Nonlinear Chemical Processes,” IEEE ... Camacho, OE, 1996, “A New Approach To Design And Tune Sliding Mode Controllers For Chemical Processes,” Ph.D ...

Research paper thumbnail of Sliding mode control: a robust approach to integrating systems with dead time

This article presents an easy way to control integrating systems using a sliding mode controller ... more This article presents an easy way to control integrating systems using a sliding mode controller based on a first-order-plus-dead-time (FOPDT) model of the process. A simple method of system identification is proposed to obtain the FOPDT model parameters. A set of tuning equations for the controller are established as functions of the parameters. Finally, an integrating chemical process is simulated and the proposed controller's performance is judged

Research paper thumbnail of A sliding mode control proposal for open-loop unstable processes

Isa Transactions, 2004

This papers presents a sliding mode controller based on a first-order-plus-dead-time model of the... more This papers presents a sliding mode controller based on a first-order-plus-dead-time model of the process for controlling open-loop unstable systems. The proposed controller has a simple and fixed structure with a set of tuning equations as a function of the desired performance. Both linear and nonlinear models were used to study the controller performance by computer simulations.

Research paper thumbnail of Una propuesta de control por modos deslizantes para procesos con tiempo muerto variable

... [4] Camacho O., C. Smith, Sliding Mode Control: An Approach To Regulate Nonlinear Chemical Pr... more ... [4] Camacho O., C. Smith, Sliding Mode Control: An Approach To Regulate Nonlinear Chemical Processes. ISA Transactions, 39, 2000, pp. ... [7] Sira-Ramirez, H., and O. Llanes-Santiago, Dynamical Discontinuous Feedback Strategies In The Regulation of Nonlinear Chemical ...

Research paper thumbnail of On Sliding Mode Control For Nonlinear Electrical Systems

This article describes the synthesis of a sliding mode controller SMCr based on a second order li... more This article describes the synthesis of a sliding mode controller SMCr based on a second order linear model using an integral-differential surface of the tracking-error. Different from similar strategies, the tuning parameters keep a close relationship with the system dynamics in terms of conventional specifications of transient response. The proposed controller only needs the output feedback of system and could be satisfactorily used in control of single input-single output nonlinear electric systems such as electronic power converters with pulse width modulation.

Research paper thumbnail of Some long time delay sliding mode control approaches

Isa Transactions, 2007

This paper presents a combined approach of predictive structures with sliding mode control (SMC).... more This paper presents a combined approach of predictive structures with sliding mode control (SMC). Control schemes have been proposed looking for performance and robustness improvement. These structures were designed for processes that can be approximated either by a first order plus time delay or an integral first order plus time delay model broadly used on chemical processes. The proposed schemes were tested for performance and robustness against set point changes and disturbances as compared with classical approaches.

Research paper thumbnail of Variable structure control applied to chemical processes with inverse response

Isa Transactions, 1999

This article proposes the use of a sliding mode controller based on a ®rst-order-plus-deadtime mo... more This article proposes the use of a sliding mode controller based on a ®rst-order-plus-deadtime model of the system for controlling higher-order chemical processes with inverse response. The controller has a simple and ®xed structure with a set of tuning equations as a function of the characteristic parameters of the ®rst order-plus-deadtime model. The controller performance was judged via computer simulations using linear and nonlinear models of chemical processes with inverse response. #

Research paper thumbnail of Allen Thomas B - Posesion RTF

A la memoria del padre William S. Bowdern, S. J.

Research paper thumbnail of Multivariate statistical analysis to detect insulin infusion set failure

Multivariate statistical analysis techniques are applied to insulin infusion set failure detectio... more Multivariate statistical analysis techniques are applied to insulin infusion set failure detection (IISF), a challenging problem faced by individuals with type 1 diabetes that are on continuous insulin infusion pump therapy. Bivariate classification (BC), principal component analysis (PCA), and a combined approach were applied to simulated glucose concentrations for 10 patients, based on a nonlinear physiological model of insulin and glucose dynamics. The PCA algorithm had fewer false alarms than BC, while detecting most drifting (ramp) infusion set failures before complete failure occurred.

Research paper thumbnail of A General Sliding Mode Controller for Nonlinear Chemical Processes

Journal of Dynamic Systems Measurement and Control-transactions of The Asme, 2000

... Sira-Ramirez, H., and Llanes-Santiago, O., 1994, “Dynamical Discontinuous Feedback Strategies... more ... Sira-Ramirez, H., and Llanes-Santiago, O., 1994, “Dynamical Discontinuous Feedback Strategies In The Regulation of Nonlinear Chemical Processes,” IEEE ... Camacho, OE, 1996, “A New Approach To Design And Tune Sliding Mode Controllers For Chemical Processes,” Ph.D ...

Research paper thumbnail of Sliding mode control: a robust approach to integrating systems with dead time

This article presents an easy way to control integrating systems using a sliding mode controller ... more This article presents an easy way to control integrating systems using a sliding mode controller based on a first-order-plus-dead-time (FOPDT) model of the process. A simple method of system identification is proposed to obtain the FOPDT model parameters. A set of tuning equations for the controller are established as functions of the parameters. Finally, an integrating chemical process is simulated and the proposed controller's performance is judged

Research paper thumbnail of A sliding mode control proposal for open-loop unstable processes

Isa Transactions, 2004

This papers presents a sliding mode controller based on a first-order-plus-dead-time model of the... more This papers presents a sliding mode controller based on a first-order-plus-dead-time model of the process for controlling open-loop unstable systems. The proposed controller has a simple and fixed structure with a set of tuning equations as a function of the desired performance. Both linear and nonlinear models were used to study the controller performance by computer simulations.

Research paper thumbnail of Una propuesta de control por modos deslizantes para procesos con tiempo muerto variable

... [4] Camacho O., C. Smith, Sliding Mode Control: An Approach To Regulate Nonlinear Chemical Pr... more ... [4] Camacho O., C. Smith, Sliding Mode Control: An Approach To Regulate Nonlinear Chemical Processes. ISA Transactions, 39, 2000, pp. ... [7] Sira-Ramirez, H., and O. Llanes-Santiago, Dynamical Discontinuous Feedback Strategies In The Regulation of Nonlinear Chemical ...

Research paper thumbnail of On Sliding Mode Control For Nonlinear Electrical Systems

This article describes the synthesis of a sliding mode controller SMCr based on a second order li... more This article describes the synthesis of a sliding mode controller SMCr based on a second order linear model using an integral-differential surface of the tracking-error. Different from similar strategies, the tuning parameters keep a close relationship with the system dynamics in terms of conventional specifications of transient response. The proposed controller only needs the output feedback of system and could be satisfactorily used in control of single input-single output nonlinear electric systems such as electronic power converters with pulse width modulation.

Research paper thumbnail of Some long time delay sliding mode control approaches

Isa Transactions, 2007

This paper presents a combined approach of predictive structures with sliding mode control (SMC).... more This paper presents a combined approach of predictive structures with sliding mode control (SMC). Control schemes have been proposed looking for performance and robustness improvement. These structures were designed for processes that can be approximated either by a first order plus time delay or an integral first order plus time delay model broadly used on chemical processes. The proposed schemes were tested for performance and robustness against set point changes and disturbances as compared with classical approaches.

Research paper thumbnail of Variable structure control applied to chemical processes with inverse response

Isa Transactions, 1999

This article proposes the use of a sliding mode controller based on a ®rst-order-plus-deadtime mo... more This article proposes the use of a sliding mode controller based on a ®rst-order-plus-deadtime model of the system for controlling higher-order chemical processes with inverse response. The controller has a simple and ®xed structure with a set of tuning equations as a function of the characteristic parameters of the ®rst order-plus-deadtime model. The controller performance was judged via computer simulations using linear and nonlinear models of chemical processes with inverse response. #

Research paper thumbnail of Allen Thomas B - Posesion RTF

A la memoria del padre William S. Bowdern, S. J.