Papers by Binoy Krishna Roy
Chaos Solitons & Fractals, Apr 1, 2022
Chaos Solitons & Fractals, Nov 1, 2022
Chaos, Solitons & Fractals
The objective of this paper is to study the chaos and multistability behaviors in a 4D dissipativ... more The objective of this paper is to study the chaos and multistability behaviors in a 4D dissipative chaotic cancer growth/decay model. The 4D chaotic cancer growth/decay model has chaotic 2-torus and 2-torus quasiperiodic unique behaviors which reflect the fact that the tumor cell density has 2-torus quasi-periodic bifurcation between two values. As the tumor cell production rate is increasing, the bifurcation is growing more rapidly as chaotic 2-torus evolution and the tumor cell density becomes unstable. The 4D cancer growth/decay model has an unstable line of equilibria with saddle-focus behavior. The chaos and multistability behaviors are explored with different qualitative and quantitative dynamic tools like Lyapunov exponents, Lyapunov dimension, bifurcation diagram and Poincaré map. Tumor cell escalation/de-escalation, glucose level, number of tumor cells are considered to analyses chaos and multistability behaviors. The existence of multistability behavior in the 4D cancer model reveals that the different phenotypes are adopted by tumor cells, some of them become metastatic, adopt different behaviors and turn into a genomic event. The multistability behavior in the 4D chaotic cancer growth/decay model may be of capital importance in the dynamic evolution of the tumor since complication may occurs even after the required therapy. Simulations are done in MATLAB environment and are presented for effective verification of numerical approach. MATLAB simulated results correspond successful achievement of the objective.
Control Instrumentation Systems, 2019
Manipulators are widely used in all areas of science and technology. Effective trajectory trackin... more Manipulators are widely used in all areas of science and technology. Effective trajectory tracking and quick deflection suppression are the two main aspect of research for a flexible manipulator. The paper reports aperiodic signal like trajectory tracking control for a planar assumed modes modelled two-link flexible manipulator (TLFM). The aperiodic chaotic signal is used as a desired trajectory for the TLFM. Thus, designing of a robust controller for the aperiodic signal tracking control is a challenging task. A backstepping based adaptive SMC technique is designed for the considered problem. In adaptive SMC, the gain of the switching control law is estimated online. The effectiveness of the considered controller is compared to an available backstepping controller. It is found that the designed backstepping based adaptive SMC perform better in terms of smaller tracking time, quick tip deflection suppression and lesser, smoother control efforts. Proposed trajectory strategy is validated on a two-link flexible manipulator in MATLAB simulation environment.
Nonlinear Dynamical Systems with Self-Excited and Hidden Attractors, 2018
In the present decade, chaotic systems are used and appeared in many fields like in information s... more In the present decade, chaotic systems are used and appeared in many fields like in information security, communication systems, economics, bioengineering, mathematics, etc. Thus, developing of chaotic dynamical systems is most interesting and desirable in comparison with dynamical systems with regular behaviour. The chaotic systems are categorised into two groups. These are (i) system with self-excited attractors and (ii) systems with hidden attractors. A self-excited attractor is generated depending on the location of its unstable equilibrium point and in such case, the basin of attraction touches the equilibria. But, in the case of hidden attractors, the basin of attraction does not touch the equilibria and also finding of such attractors is a difficult task. The systems with (i) no equilibrium point and (ii) stable equilibrium points belong to the category of hidden attractors. Recently chaotic systems with infinitely many equilibria/a line of equilibria are also considered under the cattegory of hidden attractors. Higher dimensional chaotic systems have more complexity and disorders compared with lower dimensional chaotic systems. Recently, more attention is given to the development of higher dimensional chaotic systems with hidden attractors. But, the development of higher dimensional chaotic systems having both hidden attractors and self-excited attractors is more demanding. This chapter reports three hyperchaotic and two chaotic, 5-D new systems having the nature of both the self-excited and hidden attractors. The systems have non-hyperbolic equilibria, hence, belong to the category of self-excited attractors. Also, the systems have many equilibria, and hence, may be considered under the category of a chaotic system with hidden attractors. A systematic procedure is used to develop the new systems from the well-known 3-D Lorenz chaotic system. All the five systems exhibit multistability with the change of initial conditions. Various theoretical and numerical tools like phase portrait, Lyapunov spectrum, bifurcation diagram, Poincaré map, and frequency spectrum are used to confirm the chaotic nature of the new systems.
2020 3rd International Conference on Energy, Power and Environment: Towards Clean Energy Technologies, 2021
In this paper, a deloading control technique is proposed for a photovoltaic system to regulate DC... more In this paper, a deloading control technique is proposed for a photovoltaic system to regulate DC link voltage under lightly loaded conditions. A simplified deloading control technique that can regulate the DC link voltage is proposed here for the battery bank supported PV system. In addition, the proposed control technique is implemented in field-programmable gate array (FPGA)-in-loop simulation to verify the feasibility of successful hardware implementation. The proposed controller is converted into an equivalent code in VHDL, a hardware description language. In the implementation process, the code is implemented in Zedboard (FPGA hardware), which is interfaced with MATLAB/Simulink and Vivado software. The results obtained using the FPGA-in-Loop simulation are satisfactory and maintaining the DC link voltage within the limit under both MPPT and deloading conditions.
Journal of Water Process Engineering, 2019
This paper presents an event triggered nonlinear model predictive control (NMPC) to improve the p... more This paper presents an event triggered nonlinear model predictive control (NMPC) to improve the performance of a wastewater treatment plant (WWTP). The goal of this paper is to design a simplified event triggered NMPC(ETNMPC) suitable for practical implementation. Unlike the conventional NMPC where an optimisation problem is solved at each sampling instant, in the proposed event based formulation of NMPC, the optimisation problem is re-evaluated only when a certain triggering condition is satisfied. A triggering condition is designed based on deviation of error or one step ahead prediction of error from a predefined threshold value. If one of these goes beyond the predefined threshold limit or the time gap from the triggering of last event crosses the maximum allowable time limit, a new event is triggered. The controller is designed to improve the overall performance of a WWTP by regulating two significant variables, i.e. nitrate and dissolved oxygen concentrations at some specified set-points. A conventional NMPC is also designed. The performances of the proposed controller is compared with a conventional NMPC and PI controller. Both NMPC and ETNMPC are able to improve Effluent Quality and Overall Cost Index of the WWTP when compared with PI controller, but a significant reduction in computation and communication(almost 50%) is achieved in the case of ETNMPC when compared with the conventional NMPC.
The European Physical Journal Special Topics, 2019
Abstract Flexible manipulators are being considered as bench mark control problem in the field of... more Abstract Flexible manipulators are being considered as bench mark control problem in the field of nonlinear dynamics. Many of their inherent advantages create challenges while dealing with the dynamics. Tracking control and vibration suppression are two main control problems considered. In this paper a composite controller is designed for the memristive chaotic system signal as trajectory tracking control of a two-link flexible robot manipulator. The dynamics of the flexible manipulator is modelled by using assumed modes method and divided into two subsystems using the singular perturbation technique. The subsystems are called as the slow subsystem involving rigid dynamics of the manipulator and the fast sub-system which incorporates flexible dynamics of the manipulator. Separate control techniques are designed for each subsystem. Contraction theory based controllers are designed for the slow sub-system and fast subsystem for fast trajectory tracking of signal of a memristive chaotic system and quick suppression of the link deflections. The simulation results confirm the better performances of the proposed composite technique.
The European Physical Journal Special Topics, 2019
Abstract In this paper, a new chaotic oscillator consists of a single op-amp, two capacitors, one... more Abstract In this paper, a new chaotic oscillator consists of a single op-amp, two capacitors, one resistor, one inductor, and memristive diode bridge cascaded with an inductor is proposed. The proposed chaotic oscillator has a line of equilibria. In the new oscillator circuit, negative feedback, i.e. inverting terminal of the op-amp is used, and the non-inverting terminal is grounded. The new oscillator has chaotic, periodic, quasi-periodic behaviours, as seen from the Lyapunov spectrum plots. Some more theoretical and numerical tools are used to present the dynamical behaviours of the new oscillator like bifurcation diagram, phase plot. Further, a non-singular terminal sliding mode control (N-TSMC) is designed for the suppression of the chaotic states of the new oscillator. An application of the new oscillator is shown by designing a chaos-based random number generator. Raspberry Pi 3 is used for the realisation of the random number generator.
Transport, 2019
This work deals with the development of an adaptive multisensor data fusion technique for the acc... more This work deals with the development of an adaptive multisensor data fusion technique for the accurate estimation of the trains position and velocity. The proposed technique will work with the Train Collision Avoidance System (TCAS) used in Indian railways during Global Positioning System (GPS) outages. The determination of accurate position of trains is a challenging task for the TCAS during GPS outages. The accuracy of the proposed Volterra Recursive Least Square (VRLS) based adaptive multisensor data fusion technique is evaluated by generating two kinematic profiles for a passenger train running between Silchar–Lumding broad gauge route in Indian railways. The effect of accelerometer bias is also considered during the analysis. It is observed that the developed technique can provide a better estimate of the position and velocity for the TCAS especially during GPS outages and without using any additional railway infrastructure. The simulation results indicate that the proposed tec...
IET Generation, Transmission & Distribution, 2019
The use of inertia emulation in a microgrid has been growing as a promising control approach to m... more The use of inertia emulation in a microgrid has been growing as a promising control approach to maintain the bus voltage and frequency. An inertia emulation-based control technique is proposed for a DC microgrid supplying AC loads in this study. The proposed work includes: (i) the DC bus voltage regulation using virtual inertia control and economic power management by a current sharing algorithm in cascade with a restoration control; (ii) AC load bus voltage and frequency regulation using virtual excitation emulation and inertia emulated control that utilises the emulated inertia and DC bus voltage. Further, it also provides inertia support to the grid. The coordinated current sharing algorithm manages the current (power) sharing between the grid and battery pack of electric vehicles based on electricity price and state of charge of the battery. The cascaded restoration control eliminates the steady-state error in the DC bus voltage. Finally, the DC microgrid is simulated under various operating conditions to verify the performance of the proposed control approach. The simulation results reveal that the objectives are achieved successfully.
International Journal of Dynamics and Control, 2017
This paper addresses the problem of tip trajectory tracking control along with the suppression of... more This paper addresses the problem of tip trajectory tracking control along with the suppression of tip deflection of a planar two-link flexible manipulator (TLFM). Assumed modes method is used to obtain the dynamic model of the system. A robust chattering free finite time second-order SMC is designed to address this control problem. A conventional first order sliding surfaces are designed in terms of the tracking error first. Then, the second-order sliding surfaces are designed in terms of the first order SMC. The performance metrics considered are tracking error and time of the suppression of the tip deflection. The simulation results are compared with the existing SMC based techniques for tracking control of a TLFM. Better performances of the proposed controller are visibly reflected in the simulation results in MATLAB environment. The effectiveness of the proposed tip trajectory tracking strategy is validated using numerical simulation in MATLAB environment. Keywords Second-order SMC • Tip trajectory tracking • Chattering free SMC • Tip deflection suppression • AMM Mass of link-2, m 2 = 0.0535 kg Efficiency of gear boxes, η g1 = 0.85, η g2 = 0.9 Length of link-1, L 1 = 0.202 m Efficiency of motors, η m1,2 = 0.85 Length of link-2, L 2 = 0.201 m Constants of back e. m. f, K m1 = 0.119 v/rad, K m2 = 0.0234 v/rad Resistance of Armatures, Gear ratio, K g1 = 100, K g2 = 50 R m1 = 11.5 , R m2 = 2.32 Equivalent M. I at load, Motor torque constant K t1 = 0.119 Nm/A, J eq1 = 0.17043 Kgm 2 K t2 = 0.0234 Nm/A Equivalent M. I at load, Stiffness of the link, K s1 = 22 Nm/rad, J eq2 = 0.0064387 Kgm 2 K s2 = 2.5 Nm/rad Link-1 M. I., J arm1 = 0.002035 Kgm 2 Link-2 M. I, J arm2 = 0.0007204 Kgm 2
Nonlinear Dynamics, 2018
Objectives of the paper are (1) to design two new real and complex no equilibrium point hyperchao... more Objectives of the paper are (1) to design two new real and complex no equilibrium point hyperchaotic systems, (2) to design synchronisation technique for the new systems using the contraction theory and (3) to validate the results by using circuit realisation. First a new no equilibrium point hyperchaotic system is developed using a 3-D generalised Lorenz system; then using the new system a new complex no equilibrium point hyperchaotic system is reported. Both the new systems have hidden chaotic attractors. Various dynamical behaviours are observed in the new systems like chaotic, periodic, quasi-periodic and hyperchaotic. Both the systems have inverse crisis route to chaos with the variation of parameter a and crisis route to chaos with the variation of parameters b, c and d. These phenomena along with hidden attractors in a complex hyperchaotic system are not seen in the literature. Synchronisation between the identical new hyperchaotic systems is achieved using the contraction theory. Further the synchronisation between the identical new complex hyperchaotic systems is achieved using adaptive contraction theory. The proposed synchronisation strategies are validated using the MATLAB simulation and circuit implementation results. Further, an
Optik, 2016
This paper reports a new 3-D autonomous chaotic system with novel behaviour. The proposed system ... more This paper reports a new 3-D autonomous chaotic system with novel behaviour. The proposed system has three different natures of equilibria: (i) saddle, (ii) saddle foci and (iii) stable node foci which is new in the literature. The system has invariant nature of the equilibria in the considered ranges of all five bifurcation parameters. The system has various complex dynamic behaviours like periodic (period-1, period-2, period-4), quasi-periodic, chaotic transient, stable and chaotic attractor. The system exhibits (i) inverse crises route to chaos for two bifurcation parameters and (ii) crises route to chaos for another three bifurcation parameters. It is observed that in case of normal parameter ranges, the trajectories of the system are concentrated only near an unstable equilibrium point, but in the transient chaotic parameters ranges the trajectories of the system switchover to a stable equilibrium point from the unstable equilibrium point. The transient chaotic nature of the system is analysed using the many numerical tools like Lyapunov exponents, instantaneous phase, Poincare return map, recurrence plot, 0-1 test analysis, autocorrelation plot. The findings of the numerical tools are validated using the circuit implementation.
2016 IEEE Students’ Technology Symposium (TechSym), 2016
This paper presents a new fractional-order model of a chaotic system that generates only stable e... more This paper presents a new fractional-order model of a chaotic system that generates only stable equilibria. The proposed fractional-order chaotic system (FOCS) having exponential nonlinearity, is topologically inequivalent to typical chaotic systems and challenges the conventional notion of the presence of unstable equilibria to ensure the existence of chaos in fractional dynamics. This work investigates the hidden attractor dynamics for varying fractional orders and determines the minimum commensurate dimension to display chaos. A synchronisation control scheme is put forward to indicate the practical application of the system in secure communication. Numerical simulations validate the theoretical analysis and signify that the objectives of the paper are finally achieved.
ISA Transactions, 2017
This paper presents an interesting phenomenon unobserved so far in literature to the best of the ... more This paper presents an interesting phenomenon unobserved so far in literature to the best of the authors' knowledge in fractional-order chaotic systems (FOCSs). It is the rotational phenomenon of fractionalorder coexisting attractors. Another significant feature of the newly proposed FOCS is that two 2-wing chaotic attractors coexist in its fractional-order dynamics i.e. α < 1. But once the system attains integerorder, the two attractors merge and evolve into a single 4-wing attractor. Furthermore, the authors have drawn its comparison with various well-known FOCSs to prove its superior features. In a novel attempt, the authors have utilised the property of simultaneous existence of coexisting attractors in the FOCS to carry out the synchronisation. A fractional-order circuit implementation with minimum components, has been performed using numerous audio signals with variable frequencies and amplitudes, as test signals. The objectives of the paper are finally achieved as the circuit implementation results are in perfect agreement with those of the theoretical analyses.
Uploads
Papers by Binoy Krishna Roy