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Anup K. Ekbote

Bio: Anup K. Ekbote is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Chemistry & Intersystem crossing. The author has an hindex of 2, co-authored 4 publications receiving 14 citations.

Papers
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Journal ArticleDOI
TL;DR: A wide range of MFC materials can be found in the literature, see as discussed by the authors for a survey of the most common types of luminescent materials and their properties when subjected to various mechanical stimuli.
Abstract: Mechanofluorochromic (MFC) materials are a class of luminescent materials that have ability to show changes in their emission when subjected to various mechanical stimuli. A wide range of MFC materials...

27 citations

Journal ArticleDOI
TL;DR: A terminal sliding mode control law is obtained for the linearized model of the TRMS system by transforming it to the Brunovsky canonical form and is shown to be stable to disturbances in pitch and yaw.

11 citations

Journal ArticleDOI
TL;DR: In this paper, the authors deal with the finite-time control of a quadrotor unmanned aerial vehicle about the hovering position by converting the linearized model to its Brunovský canonical form.

2 citations

Journal ArticleDOI
TL;DR: In this paper , the effect of different substituents at the ortho position of the pyridine ring was investigated, and the results indicated that heavy atoms in organic fluorophores can be used as a new design strategy to obtain mechanoluminescent materials.
Abstract: Pyridine-based derivatives Py-1, Py-2, and Py-3 were synthesized by the Suzuki cross-coupling reaction, and the effect of different substituents at the ortho position of the pyridine ring was investigated. In the molecular framework of push–pull compounds, electron acceptor (A) pyridine was substituted with an electron donor (D) dimethoxy triphenylamine unit. The effect of passing from a dipolar (D-A, Py-1) to a quadrupolar (D-A-D, Py-3) structure as well as the impact of functionalizing the pyridine with a bromine in the dipolar structure (D-A-Br, Py-2) was investigated. All the pyridine derivatives were found to be highly emissive both in solution and in the solid state, with fluorescence properties markedly sensitive to the environment and responsive to external stimuli. The spectral and photophysical properties in solution were investigated through conventional steady-state and advanced time-resolved spectroscopies with nanosecond and femtosecond temporal resolution. The expected efficient intersystem crossing for the heavy-atom-containing molecule was surprisingly not highlighted by our experiments, but an increased push–pull character was enabled by functionalizing the pyridine acceptor with the bromine. The ultrafast spectroscopic study revealed a peculiar excited state deactivation mechanism for the Br derivative among the others, involving photoinduced intramolecular charge transfer accompanied by twisting of the molecular structure (population of a TICT excited state). Similarly, a significant color change in the solid-state emission was observed for Py-2 upon mechanical grinding, suggesting a mechanochromic luminescence behavior in this case. Our findings suggest introducing heavy atoms in organic fluorophores as a new design strategy to obtain mechanoluminescent materials.

1 citations

Posted Content
TL;DR: A simple configuration error function with an appropriately defined transport map is proposed to extract feedforward and proportional-derivative control law for position and line-of-sight stabilization of the nonholonomic spherical robot actuated by three independent actuators.
Abstract: In this paper we present a geometric control law for position and line-of-sight stabilization of the nonholonomic spherical robot actuated by three independent actuators A simple configuration error function with an appropriately defined transport map is proposed to extract feedforward and proportional-derivative control law Simulations are provided to validate the controller performance

1 citations


Cited by
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Journal ArticleDOI
01 Mar 2018-Optik
TL;DR: In this paper, an observer-based robust controller is proposed to attenuate the chattering effect of the sliding mode control in a two-rotor mimo system, and exponential stability is guaranteed by using the Lyapunov method.

25 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a new method to tune a fractional-order Proportional-Integral-Derivative controller for a twin rotor aerodynamic system, which is a nonlinear highly coupled MIMO system.
Abstract: 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.

21 citations

Proceedings ArticleDOI
01 Jan 2004
TL;DR: In this paper, the task of complete reconfiguration of a rolling sphere is recast as a problem in planar geometry, and two control points are defined that equivalently represent the configuration of the sphere.
Abstract: 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

12 citations