The Pharmacological Basis of Therapeutics A Textbook of Pharmacology, Toxicology and Therapeutics for Physicians and Medical Students. By Prof. Louis Goodman and Prof. Alfred Gilman. Pp. xiii + 1383. (New York: The Macmillan Company, 1941.) 50s. net.

The Pharmacological Basis of Therapeutics

In this paper, sliding-mode control is applied on multi-input/multi-output (MIMO) nonlinear systems. A novel approach is proposed, which allows chattering reduction on control input while keeping high tracking performance of the controller in steady-state regime. This approach consists of designing a nonlinear reaching law by using an exponential function that dynamically adapts to the variations of the controlled system. Experimental study was focused on a MIMO modular robot arm. Experimental results are presented to show the effectiveness of the proposed approach, regarding particularly the chattering reduction on control input in steady-state regime.

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Sliding-Mode Robot Control With Exponential Reaching Law

A new approach for the design of sliding mode controllers based on a first-order-plus-deadtime model of the process, is developed. This approach results in a fixed structure controller with a set of tuning equations as a function of the characteristic parameters of the model. The controller performance is judged by simulations on two nonlinear chemical processes

http://webdelprofesor.ula.ve/ingenieria/ocamacho/publicaciones/ISAT-99016.pdf

Sliding mode control: an approach to regulate nonlinear chemical processes

In this article, a second-order sliding mode control (2-SMC) is proposed for second-order uncertain plants using equivalent control approach to improve the performance of control systems. A Proportional + Integral + Derivative (PID) sliding surface is used for the sliding mode. The sliding mode control law is derived using direct Lyapunov stability approach and asymptotic stability is proved theoretically. The performance of the closed-loop system is analysed through an experimental application to an electromechanical plant to show the feasibility and effectiveness of the proposed second-order sliding mode control and factors involved in the design. The second-order plant parameters are experimentally determined using input-output measured data. The results of the experimental application are presented to make a quantitative comparison with the traditional (first-order) sliding mode control (SMC) and PID control. It is demonstrated that the proposed 2-SMC system improves the performance of the closed-loop system with better tracking specifications in the case of external disturbances, better behavior of the output and faster convergence of the sliding surface while maintaining the stability.

Second-order sliding mode control with experimental application.

Challenges and Recent Progress in the Development of a Closed-loop Artificial Pancreas

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

Variable structure control applied to chemical processes with inverse response

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.

Some long time delay sliding mode control approaches

This paper presents the design of a robust PID controller for a four quadrant DC to AC switched mode inverter, using a buckboost DC to DC converter. The designed controller is intended to decrease the total harmonic distortion (THD) in the output voltage against sudden load changes. The proposed robust controller is based in a classical two degree of freedom approach. The controller performance was tested by computer simulations.

Robust PID control of a buck-boost DC-AC converter

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.

A sliding mode control proposal for open-loop unstable processes.

A strategy to regulate unstable processes using a modified Smith predictor based sliding mode controller (SP-SMC) is illustrated. The proposed scheme presents disturbance rejection and optimal control input usage with overall improved regulatory performances. The unstable process with time delay is first estimated using a simple measurement of limit cycle output obtained from a modified relay experiment. Then this paper extends a work on SP-SMC for unstable processes, which leads to significant improvements in its regulatory capacities of reference inputs and disturbances. A new control law is incorporated in the discontinuous part of sliding mode control such that the overall performance improves significantly. The metaheuristic search algorithm with some modifications has been implemented successfully to satisfy the new control performance index. The robustness of the controller is also tested under the process uncertainty. Illustrative examples show the simplicity and superiority of the presented desig...

/pdf/smith-predictor-based-sliding-mode-control-for-a-class-of-ijg0prma6p.pdf

Rubén Rojas

Papers

Variable structure control applied to chemical processes with inverse response

Some long time delay sliding mode control approaches

Robust PID control of a buck-boost DC-AC converter

A sliding mode control proposal for open-loop unstable processes.

Smith predictor based sliding mode control for a class of unstable processes