Continuous Stability TS Fuzzy Systems Novel Frame Controlled by a Discrete Approach and Based on SOS Methodology

Generally, the continuous and discrete TS fuzzy systems’ control is studied independently. Unlike the discrete systems, stability results for the continuous systems suffer from conservatism because it is still quite difficult to apply non-quadratic Lyapunov functions, something which is much easier for the discrete systems. In this paper and in order to obtain new results for the continuous case, we proposed to connect the continuous with the discrete cases and then check the stability of the continuous TS fuzzy systems by means of the discrete design approach. To this end, a novel frame was proposed using the sum of square approach (SOS) to check the stability of the continuous Takagi Sugeno (TS) fuzzy models based on the discrete controller. Indeed, the control of the continuous TS fuzzy models is ensured by the discrete gains obtained from the Euler discrete form and based on the non-quadratic Lyapunov function. The simulation examples applied for various models, by modifying the order of the Euler discrete fuzzy system, are presented to show the effectiveness of the proposed methodology.

An Emotional Discrete Controller PSO Tuned and PLC Implemented for a Real Industrial Pumping System

The application of automation techniques to water pump systems, combined with modern control techniques, has been increasing the hydraulic and energy efficiency of such systems. In this context, the objective of this work is to present an intelligent method of flow control based on Brain’s Emotional Learning (BELBIC), which will be applied to an experimental workbench of a pumping system, located in the Energy Efficiency and Energy Quality Laboratory (LEEQE) at Federal University of Pernambuco (UFPE). The parameters of this controller are optimized with a particle swarm optimization (PSO) technique with minimization of Integral Absolute Error (IAE). Initial tests were performed in a computational environment so that the system’s performance could be pre-tested, thereby the dynamics of the system was modeled from real data generated in the process. The experimental results were obtained through the implementation of this control system in a programmable logic controller (PLC), which was the device responsible for all the automation of the workbench previously mentioned. The data of this workbench were collected using a supervisory system exclusively developed for this work. These data were then used to analyze the performance of the proposed control system, which demonstrated that its behavior was efficient.

Event-Based, Intermittent, Discrete Adaptive Control for Speed Regulation of Artificial Legs

For artificial legs that are used in legged robots, exoskeletons, and prostheses, it suffices to achieve velocity regulation at a few key instants of swing rather than tight trajectory tracking. Here, we advertise an event-based, intermittent, discrete controller to enable set-point regulation for problems that are traditionally posed as trajectory following. We measure the system state at prior-chosen instants known as events (e.g., vertically downward position), and we turn on the controller intermittently based on the regulation errors at the set point. The controller is truly discrete, as these measurements and controls occur at the time scale of the system to be controlled. To enable set-point regulation in the presence of uncertainty, we use the errors to tune the model parameters. We demonstrate the method in the velocity control of an artificial leg, a simple pendulum, with up to 50% mass uncertainty. Starting with a 100% regulation error, we achieve velocity regulation of up to 10% in about five swings with only one measurement per swing.

The assembly of the controller

The assembly of the control controller for controlling an electronic start-up control device is described. The technical characteristics of the controller are given. The list of commands supported by the controller when exchanging via the RS485 interface and additional discrete controller signals is presented.

ALGORITHMS FOR SYNTHESIS OF DISCRETE CONTROLLERS IN NONLINEAR CONTROL SYSTEMS WITH DELAY

Algorithms for the synthesis of discrete controllers in nonlinear control systems, taking into account the delay, have been proposed. The synthesized vector controller provides a solution to the control problem, for example, the translation of the image point of a closed system from arbitrary initial conditions to the origin of the phase space coordinates. Built on the basis of a series-parallel set of invariant manifolds, the dynamic discrete controller ensures the fulfillment of the specified technological requirements, the asymptotic stability of a closed discrete-continuous system, and has the property of predicting the behavior of the system after sampling. These algorithms have made it possible to effectively solve the problems of synthesis of discrete controllers, taking into account the delay in process control systems.