Real Time Implementation of non Linear Observer-Based Fuzzy Sliding Mode Controller for a twin rotor multi-input multi-output system (TRMS)

This paper proposes a new method to tune a fractional-order Proportional–Integral–Derivative controller (also called \(\mathrm {P}\mathrm {I}^{\uplambda }\mathrm {D}^{\upmu }\) ) for a Twin Rotor Aerodynamic System, which is a nonlinear highly coupled Multi-Input–Multi-Output system. The five parameters of the controller are tuned using optimization to minimize a performance index which is a weighted sum of absolute values of four frequency domain specifications: gain crossover frequency, phase margin, ISO damping property (to be robust against process gain variation), and magnitude peak value at the resonant frequency, where the latter is the new control design specification that is suggested by this paper. The performance of the proposed controller is compared with that of an integer-order Proportional–Integral–Derivative (PID) controller. Simulation results shows that the fractional-order controller outperforms its integer-order counterpart in minimizing the performance index, which results in satisfying the required design specification more accurately. This is demonstrated by first testing the performance of the of the closed-loop system where the fractional-order controller gives better performance than the integer-order controller and second by testing the robustness of the system by changing one of the process parameters, where the fractional-order controller is much more robust, unlike the integer-order controller where the closed-loop system becomes unstable.

A New Method to Tune a Fractional-Order PID Controller for a Twin Rotor Aerodynamic System

On The Modeling of Twin Rotor MIMO System Using Chirp Inputs as Test Signals

The task of complete reconfiguration of a rolling sphere is recast as a problem in planar geometry. Based on our specific choice of coordinate system, two control points are defined that equivalently represent the configuration of the sphere. Under the applied control inputs, the trajectories of these control points are shown to form an evolute-involute pair. The objective of complete reconfiguration is then captured within integral conditions over the path of the control points. A class of solution to the geometric problem is derived and a three step algorithm for complete reconfiguration is proposed. The solution is computationally in-expensive and is confirmed by simulation results.Copyright © 2004 by ASME

Reconfiguration of a Rolling Sphere: A Problem in Evolute-Involute Geometry

Nonlinear Cascade-Based Control for a Twin Rotor MIMO System

Semistability Analysis of the Chaplygin Sleigh and Nonsmooth Mechanical Oscillator

In this study, we report a comprehensive time-resolved spectroscopic investigation of the excited-state deactivation mechanism in three push–pull isomers characterized by a phenothiazine electron donor, a benzothiazole electron acceptor, and a phenyl π-bridge where the connection is realized at the relative ortho, meta, and para positions. Spin–orbit charge-transfer-induced intersystem crossing takes place with high yield in these all-organic donor–acceptor compounds, leading also to efficient production of singlet oxygen. Our spectroscopic results give clear evidence of room-temperature phosphorescence not only in solid-state host–guest matrices but also in highly biocompatible aggregates of these isomers produced in water dispersions, as rarely reported in the literature. Moreover, aggregates of the isomers could be internalized by lung cancer and melanoma cells and display bright luminescence without any dark cytotoxic effect. On the other hand, the isomers showed significant cellular phototoxicity against the tumor cells due to light-induced reactive oxygen species generation. Our findings strongly suggest that nanoaggregates of the investigated isomers are promising candidates for imaging-guided photodynamic therapy.

Anup K. Ekbote

Papers

Semistability Analysis of the Chaplygin Sleigh and Nonsmooth Mechanical Oscillator

Room-Temperature Phosphorescence and Cellular Phototoxicity Activated by Triplet Dynamics in Aggregates of Push–Pull Phenothiazine-Based Isomers