Anish Acharya | Jadavpur University (original) (raw)

Papers by Anish Acharya

Research paper thumbnail of Optimized quality factor of fractional order analog filters with band-pass and band-stop characteristics

… (ICCCNT), 2012 Third …, 2012

Fractional order (FO) filters have been investigated in this paper, with band-pass (BP) and band-... more Fractional order (FO) filters have been investigated in this paper, with band-pass (BP) and band-stop (BS) characteristics, which can not be achieved with conventional integer order filters with orders lesser then two. The quality factors for symmetric and asymmetric magnitude response have been optimized using real coded Genetic Algorithm (GA) for a user specified center frequency. Parametric influence of the FO filters on the magnitude response is also illustrated with credible numerical simulations.

Research paper thumbnail of Least square and Instrumental Variable system identification of ac servo position control system with fractional Gaussian noise

Energy, Automation, and …, 2011

In this paper, the classical Least Square Estimator (LSE) and its improved version the Instrument... more In this paper, the classical Least Square Estimator (LSE) and its improved version the Instrumental Variable (IV) estimator have been used for the identification of an ac servo motor position control system. The data for system identification has been collected from a practical test set-up for fixed command on the final angular position of the servo motor with varying level

Research paper thumbnail of Stability analysis of delayed system using Bode integral

Computer Communication and …, 2013

The PID controller parameters can be adjusted in such a manner that it gives the desired frequenc... more The PID controller parameters can be adjusted in such a manner that it gives the desired frequency response and the results are found using the Bode's integral formula in order to adjust the slope of the nyquist curve in a desired manner. The same idea is applied for plants with time delay . The same has also been done in a new approach . The delay term is approximated as a transfer function using Padé approximation and then the Bode integral is used to determine the controller parameters. Both the methodologies are demonstrated with MATLAB simulation of representative plants and accompanying PID controllers. A proper comparison of the two methodologies is also done. The PID controller parameters are also tuned using a real coded Genetic Algorithm (GA) and a proper comparison is done between the three methods.

Research paper thumbnail of Identification of nonlinear systems from the knowledge around different operating conditions: A feed-forward multi-layer ANN based approach

… Distributed and Grid …, 2012

The paper investigates nonlinear system identification using system output data at various linear... more The paper investigates nonlinear system identification using system output data at various linearized operating points. A feed-forward multi-layer Artificial Neural Network (ANN) based approach is used for this purpose and tested for two target applications i.e. nuclear reactor power level monitoring and an AC servo position control system. Various configurations of ANN using different activation functions, number of hidden layers and neurons in each layer are trained and tested to find out the best configuration. The training is carried out multiple times to check for consistency and the mean and standard deviation of the root mean square errors (RMSE) are reported for each configuration.

Research paper thumbnail of Extending the Concept of Analog Butterworth Filter for Fractional Order Systems

Signal Processing, 2012

This paper proposes the design of Fractional Order (FO) Butterworth filter in complex w-plane (w=... more This paper proposes the design of Fractional Order (FO) Butterworth filter in complex w-plane (w=s q ; q being any real number) considering the presence of under-damped, hyper-damped, ultra-damped poles. This is the first attempt to design such fractional Butterworth filters in complex w-plane instead of complex s-plane, as conventionally done for integer order filters. Firstly, the concept of fractional derivatives and w-plane stability of linear fractional order systems are discussed. Detailed mathematical formulation for the design of fractional Butterworth-like filter (FBWF) in w-plane is then presented. Simulation examples are given along with a practical example to design the FO Butterworth filter with given specifications in frequency domain to show the practicability of the proposed formulation.

Research paper thumbnail of Optimum PID control of multi-wing attractors in a family of Lorenz-like chaotic systems

Computing Communication & …, 2012

Multi-wing chaotic attractors are highly complex nonlinear dynamical systems with higher number o... more Multi-wing chaotic attractors are highly complex nonlinear dynamical systems with higher number of index-2 equilibrium points. Due to the presence of several equilibrium points, randomness of the state time series for these multi-wing chaotic systems is higher than that of the conventional double wing chaotic attractors. A real coded Genetic Algorithm (GA) based global optimization framework has been presented in this paper, to design optimum PID controllers so as to control the state trajectories of three different multi-wing Lorenz like chaotic systems viz. Lu, Rucklidge and Sprott-1 system.

Research paper thumbnail of Optimized quality factor of fractional order analog filters with band-pass and band-stop characteristics

… (ICCCNT), 2012 Third …, 2012

Fractional order (FO) filters have been investigated in this paper, with band-pass (BP) and band-... more Fractional order (FO) filters have been investigated in this paper, with band-pass (BP) and band-stop (BS) characteristics, which can not be achieved with conventional integer order filters with orders lesser then two. The quality factors for symmetric and asymmetric magnitude response have been optimized using real coded Genetic Algorithm (GA) for a user specified center frequency. Parametric influence of the FO filters on the magnitude response is also illustrated with credible numerical simulations.

Research paper thumbnail of Least square and Instrumental Variable system identification of ac servo position control system with fractional Gaussian noise

Energy, Automation, and …, 2011

In this paper, the classical Least Square Estimator (LSE) and its improved version the Instrument... more In this paper, the classical Least Square Estimator (LSE) and its improved version the Instrumental Variable (IV) estimator have been used for the identification of an ac servo motor position control system. The data for system identification has been collected from a practical test set-up for fixed command on the final angular position of the servo motor with varying level

Research paper thumbnail of Stability analysis of delayed system using Bode integral

Computer Communication and …, 2013

The PID controller parameters can be adjusted in such a manner that it gives the desired frequenc... more The PID controller parameters can be adjusted in such a manner that it gives the desired frequency response and the results are found using the Bode's integral formula in order to adjust the slope of the nyquist curve in a desired manner. The same idea is applied for plants with time delay . The same has also been done in a new approach . The delay term is approximated as a transfer function using Padé approximation and then the Bode integral is used to determine the controller parameters. Both the methodologies are demonstrated with MATLAB simulation of representative plants and accompanying PID controllers. A proper comparison of the two methodologies is also done. The PID controller parameters are also tuned using a real coded Genetic Algorithm (GA) and a proper comparison is done between the three methods.

Research paper thumbnail of Identification of nonlinear systems from the knowledge around different operating conditions: A feed-forward multi-layer ANN based approach

… Distributed and Grid …, 2012

The paper investigates nonlinear system identification using system output data at various linear... more The paper investigates nonlinear system identification using system output data at various linearized operating points. A feed-forward multi-layer Artificial Neural Network (ANN) based approach is used for this purpose and tested for two target applications i.e. nuclear reactor power level monitoring and an AC servo position control system. Various configurations of ANN using different activation functions, number of hidden layers and neurons in each layer are trained and tested to find out the best configuration. The training is carried out multiple times to check for consistency and the mean and standard deviation of the root mean square errors (RMSE) are reported for each configuration.

Research paper thumbnail of Extending the Concept of Analog Butterworth Filter for Fractional Order Systems

Signal Processing, 2012

This paper proposes the design of Fractional Order (FO) Butterworth filter in complex w-plane (w=... more This paper proposes the design of Fractional Order (FO) Butterworth filter in complex w-plane (w=s q ; q being any real number) considering the presence of under-damped, hyper-damped, ultra-damped poles. This is the first attempt to design such fractional Butterworth filters in complex w-plane instead of complex s-plane, as conventionally done for integer order filters. Firstly, the concept of fractional derivatives and w-plane stability of linear fractional order systems are discussed. Detailed mathematical formulation for the design of fractional Butterworth-like filter (FBWF) in w-plane is then presented. Simulation examples are given along with a practical example to design the FO Butterworth filter with given specifications in frequency domain to show the practicability of the proposed formulation.

Research paper thumbnail of Optimum PID control of multi-wing attractors in a family of Lorenz-like chaotic systems

Computing Communication & …, 2012

Multi-wing chaotic attractors are highly complex nonlinear dynamical systems with higher number o... more Multi-wing chaotic attractors are highly complex nonlinear dynamical systems with higher number of index-2 equilibrium points. Due to the presence of several equilibrium points, randomness of the state time series for these multi-wing chaotic systems is higher than that of the conventional double wing chaotic attractors. A real coded Genetic Algorithm (GA) based global optimization framework has been presented in this paper, to design optimum PID controllers so as to control the state trajectories of three different multi-wing Lorenz like chaotic systems viz. Lu, Rucklidge and Sprott-1 system.