Mohammad Bilal Malik - Academia.edu (original) (raw)

Papers by Mohammad Bilal Malik

2016 International Conference on Computing, Electronic and Electrical Engineering (ICE Cube), 2016

A particle filter based approach for discrete time equivalent model of an under actuated spinning... more A particle filter based approach for discrete time equivalent model of an under actuated spinning body is proposed. The presented work is a sequel to the earlier work done by the authors for the orientation control of the under actuated systems. Due to practical limitation of the system, there is an additional constraint on the actuating signal. The amplitude of the actuating signal is fixed and the Pulse width or duration of the pulse can vary. A novel approach based on particle filter is developed. The values of pulse width and amplitude of the control input are generated through a novel technique based on particle filter theory, to generate the actuating signal. The simulations are included to compare proposed techniques with the earlier developed techniques for similar systems.

2013 10th International Computer Conference on Wavelet Active Media Technology and Information Processing (ICCWAMTIP), 2013

In this paper, we present modeling of two phase Permanent Magnet BrushLess DC (PMBLDC) motor in M... more In this paper, we present modeling of two phase Permanent Magnet BrushLess DC (PMBLDC) motor in Maxwell 3D software. Electromagnetic simulations and performance analysis of proposed model is carried out. Torque and back EMF equations for proposed model are derived and verified through simulations. Electromagnetic simulations include flux flow pattern, parametric analysis and transient analysis. Simulations verify that proposed model is valid, accurate and application specific. Due to its compact size, high torque and accuracy, the proposed model of two phase PMBLDC motor can be used in motion control, precise positioning, robotics, computer peripherals and automotive industry etc.

2013 IEEE 3rd International Conference on System Engineering and Technology, 2013

ABSTRACT

Transactions of the Institute of Measurement and Control, 2018

In this paper, we present a receding horizon observer for linear time-varying systems. Our main c... more In this paper, we present a receding horizon observer for linear time-varying systems. Our main contribution is that known deterministic input has been fully dealt with. This poses considerable challenges for recursive formulation of the filter. The suggested observer can be used in closed-loop feedback control systems. The existing finite memory filters lack this ability. First- and second-order statistical convergence analysis carried out in this paper provide an insight into the stochastic behaviour of the observer. Some examples demonstrate the utility of the proposed filter.

2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE), 2014

ABSTRACT

2020 IEEE 17th International Conference on Smart Communities: Improving Quality of Life Using ICT, IoT and AI (HONET), 2020

This paper solves the tracking problem for feedback linearizable sampled data nonlinear systems. ... more This paper solves the tracking problem for feedback linearizable sampled data nonlinear systems. The conversion of a continuous system into its sampled data equivalent has been discussed and the proposed control law has been derived. In classical control theory, high gain observers based feedback control has been adopted for stabilizing a nonlinear system and state estimation to track a varying reference, but it compromises the main design purpose. The proposed scheme uses augmented state estimation technique to find the additional compensation to be applied at input channel to minimize the tracking error. The results are shown through an illustrative example of an inverted pendulum system that verifies the effectiveness of the proposed scheme.

Modelling for Orientation control of a Drill Machine belonging to a class of under actuated syste... more Modelling for Orientation control of a Drill Machine belonging to a class of under actuated system is presented. The orientation control along x-axis and y-axis of the drill machine is achieved through a single pair of electromagnetic poles. Based on the concept of pulse width modulation a controlling signal for the actuators which caters for all practical limitations of the system is generated. The derived discrete time equivalent model overcomes the practical limitation of control techniques used for such class of systems. It also opens a new dimension especially for under-actuated and non-linear systems which are otherwise difficult rather impossible through orthodox control schemes. A closed form based on discrete time equivalent model supported by simulation results will be helpful in designing overall feedback control for the orientation of the system.

2016 IEEE Asia-Pacific Conference on Applied Electromagnetics (APACE), 2016

Signal processing algorithms are widely used in various applications to find position, range and ... more Signal processing algorithms are widely used in various applications to find position, range and velocity of moving objects. Signal processor part of radar has to perform heavy computations. The time required to localize the target is also critical for surveillance. When target is approaching the radar, detection needs to be faster. A radar signal processor is proposed which is capable of finding range and Doppler with variable processing times for two set of target ranges. The proposed algorithm saves processing time for short range set by reducing the computations involved in FFT stage of conventional two dimensional algorithm. For longer range set, the conventional two dimensional algorithm is used for achieving higher processing gain. It is shown that the modified approach saves much time as compared to the conventional algorithm. The proposed algorithm with reduced processing time can also be useful for long range set if high gain transmitter or better LNA is used at the receiv...

Pakistan Journal of Engineering and Applied Sciences, 2016

A pulse width modulation (PWM) approach based on the discrete equivalent model of an under actuat... more A pulse width modulation (PWM) approach based on the discrete equivalent model of an under actuated spinning body is proposed. The presented work is a sequel to the earlier work done by the authors for the orientation control of the drill machine. The constraint is an actuating signal of fixed amplitude with adjustable pulse width. A novel approach based on error minimization is developed. The optimized values of pulse width and phase of the control input are estimated to generate the actuating signal. The problems of local minima and non-causality were also addressed through proposed technique. The simulations are included to compare proposed techniques with the earlier developed techniques for similar systems. The performance is also shown under both nominal and parameter variations.

Mehran University Research Journal of Engineering and Technology, 2017

The localization of targets has been presented in this article. DOA (Direction of Arrival) is an ... more The localization of targets has been presented in this article. DOA (Direction of Arrival) is an important parameter to be determined by radar. The MLE (Maximum Likelihood Estimator) has been widely used to accurately and efficiently estimate the DOAs of multiple targets. The targets at different ranges result in a variation in amplitude of the received signals, so an MLE estimator has to operate at all ranges. For accurate results of DOA, the complex amplitudes of multiple targets should not be much different and also the prior information of Doppler and number of targets is required. In this paper, an approach is proposed which uses the classical 2D algorithm to estimate range, Doppler and number of targets and then FDA (Frequency Diversity Array) is used to focus power in a particular range. As a result, the MLE can get data from a particular range cell where all targets have almost same amplitude and thus MLE can accurately estimate the DOAs of multiple targets. Simulations and results have confirmed the effectiveness of proposed approach.

IEEE Access, 2018

In this paper, a novel continuous sampled-data observer for linear time-varying systems is presen... more In this paper, a novel continuous sampled-data observer for linear time-varying systems is presented. The proposed observer is based on two different impulsive observers. The state estimates of these impulsive observers are fused in a manner such that continuous state estimation is achieved. Another significant contribution is comprehensive stability analysis of the proposed observer. The analysis establishes conditions that guarantee exponential convergence of observers. Contrary to the common understanding, it is revealed that the convergence of associated discrete-time equation for impulsive observers is not a sufficient condition for overall convergence. Contributions are illustrated by simulations. INDEX TERMS Sampled-data, linear time varying system, impulsive observer.

2016 Chinese Control and Decision Conference (CCDC), 2016

This paper tackles the problem of impulsive observer design for the class of linear time invarian... more This paper tackles the problem of impulsive observer design for the class of linear time invariant system with sampled outputs. The proposed design approach includes continuous-time evolution and discrete jumps at specified time instants. The resulting observer is capable to track the system states in a predefined finite time. The estimation error is shown to be uniformly exponentially stable for any applicable convergence time selected under non-pathological sampling. The performance of this scheme is illustrated with an example to show the convergence behavior and its applicability.

2015 6th International Conference on Modeling, Simulation, and Applied Optimization (ICMSAO), 2015

To have complete information about a target which is detected in RADAR requires its range, veloci... more To have complete information about a target which is detected in RADAR requires its range, velocity/Doppler and Direction of arrival information. RADAR capable of finding all these 3 characteristics of targets can be connected with a network so that targets can be tracked and destroyed using the information. This paper presents Modeling and Simulation results of a 3-D RADAR.

2015 12th International Bhurban Conference on Applied Sciences and Technology (IBCAST), 2015

Robust controller design in presence of disturbance and system parameter uncertainties has been a... more Robust controller design in presence of disturbance and system parameter uncertainties has been a challenging task. In this paper attitude control of ECP 750 Gyroscope in presence of uncertainties is solved using LMI based multi objective state feedback H2 /H∞ controller. The attitude control problem addressed here resembles the formulation of polytopic model of MIMO gyroscope model to cater the parameter uncertainty and subsequent robust controller design using LMI framework is novelty of this work. MATLAB simulation results show better robust attitude control and disturbance rejection.

Proceedings of the Eighth International Symposium on Signal Processing and Its Applications, 2005.

This paper investigates the ability of state space least mean square (SSLMS) algorithm to track a... more This paper investigates the ability of state space least mean square (SSLMS) algorithm to track a chirped signal buried in additive white Gaussian noise. The signal is a sinusoid whose frequency is drifting at a constant rate. After incorporating second order linear time varying state space model of the chirped sinusoid, SSLMS exhibits superior tracking performance over standard LMS & RLS and their known variants. The step size parameter plays an important role in this context. For various values of step size parameter, time average auto-correlation function (ACF) of prediction error is evaluated when responding to chirped signal. Whiteness of prediction error verifies excellent tracking by SSLMS.

2013 IEEE International Conference on Smart Instrumentation, Measurement and Applications (ICSIMA), 2013

A sampled-data regulation problem for a class of continuous time varying systems is presented. Th... more A sampled-data regulation problem for a class of continuous time varying systems is presented. The main constraint is the availability of only the samples of the output for measurement. The particular focus is on such linear time varying systems that can be transformed into linear time invariant systems through sinusoidal transformation. This converts the problem of tracking a constant signal into a sinusoidal signal. Typical to the sampled-data control problems, the control input is generated by a discrete controller along with a discrete observer for state and disturbance estimation. A realizable reconstruction filter, which is a reduced order specialized generalized hold device, connects the discrete controller with the continuous input of the system. The resultant linear time invariant system along with the realizable reconstruction filter is thus presented as a linear impulsive system. The rest of the problem is similar to the classical regulator theory. As an example the control of gyroscope in both perturbed and unperturbed scenarios is presented.

Robotica, 2014

SUMMARYThis paper proposes a solution to the sampled-data regulation problem for feedback lineari... more SUMMARYThis paper proposes a solution to the sampled-data regulation problem for feedback linearizable n-link robotic manipulators. The prime focus is on the development and stability analysis of the proposed control scheme in the presence of model uncertainties and external disturbances. A major constraint is the availability of sampled measurements of output signal. This leads to designing an impulsive observer for feedback linearization. The discrete-time control input is mapped into its continuous-time counterpart using a realizable reconstruction filter (RRF). The underlying control scheme relies on the sampled-data regulator theory based on the discrete-time equivalence of the plant and RRF modeled as impulsive system. This method leads to controller/observer design in discrete time. The working of the entire scheme is dependent on the stability of impulsive observer; hence a Lyapunov-based stability analysis is also included to ensure the stability of a closed-loop system. Th...

2011 9th IEEE International Conference on ASIC, 2011

A realizable reconstruction filter is presented. Since the standard reconstruction filters are no... more A realizable reconstruction filter is presented. Since the standard reconstruction filters are not realizable, our aim is to produce a reconstruction filter as an impulsive system that contains the dynamics of the reference signal. The proposed design is a memory less system and is able to overcome the intersampling behavior when applied in the closed loop system. As compared to other techniques such as generalized sampled data hold devices being used this design does not require the input and output of the reconstruction filter to be of different dimensions.

International Journal of Computer Theory and Engineering, 2012

In this paper output regulation problem for sampled-data systems with constant exogenous signals ... more In this paper output regulation problem for sampled-data systems with constant exogenous signals is considered. A discrete output feedback controller is designed under the assumption that the regulator equation in discrete-time has a solution. Discretization of the plant and exosystem is carried out by zero order hold equivalence. The goal is to design the complete controller/observer in discrete domain. As an application magnetic levitation is discussed. The simulation results along with the comparison with the continuous-time controller show the effectiveness of the proposed controller.

2016 International Conference on Computing, Electronic and Electrical Engineering (ICE Cube), 2016

A particle filter based approach for discrete time equivalent model of an under actuated spinning... more A particle filter based approach for discrete time equivalent model of an under actuated spinning body is proposed. The presented work is a sequel to the earlier work done by the authors for the orientation control of the under actuated systems. Due to practical limitation of the system, there is an additional constraint on the actuating signal. The amplitude of the actuating signal is fixed and the Pulse width or duration of the pulse can vary. A novel approach based on particle filter is developed. The values of pulse width and amplitude of the control input are generated through a novel technique based on particle filter theory, to generate the actuating signal. The simulations are included to compare proposed techniques with the earlier developed techniques for similar systems.

2013 10th International Computer Conference on Wavelet Active Media Technology and Information Processing (ICCWAMTIP), 2013

In this paper, we present modeling of two phase Permanent Magnet BrushLess DC (PMBLDC) motor in M... more In this paper, we present modeling of two phase Permanent Magnet BrushLess DC (PMBLDC) motor in Maxwell 3D software. Electromagnetic simulations and performance analysis of proposed model is carried out. Torque and back EMF equations for proposed model are derived and verified through simulations. Electromagnetic simulations include flux flow pattern, parametric analysis and transient analysis. Simulations verify that proposed model is valid, accurate and application specific. Due to its compact size, high torque and accuracy, the proposed model of two phase PMBLDC motor can be used in motion control, precise positioning, robotics, computer peripherals and automotive industry etc.

2013 IEEE 3rd International Conference on System Engineering and Technology, 2013

ABSTRACT

Transactions of the Institute of Measurement and Control, 2018

In this paper, we present a receding horizon observer for linear time-varying systems. Our main c... more In this paper, we present a receding horizon observer for linear time-varying systems. Our main contribution is that known deterministic input has been fully dealt with. This poses considerable challenges for recursive formulation of the filter. The suggested observer can be used in closed-loop feedback control systems. The existing finite memory filters lack this ability. First- and second-order statistical convergence analysis carried out in this paper provide an insight into the stochastic behaviour of the observer. Some examples demonstrate the utility of the proposed filter.

2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE), 2014

ABSTRACT

2020 IEEE 17th International Conference on Smart Communities: Improving Quality of Life Using ICT, IoT and AI (HONET), 2020

This paper solves the tracking problem for feedback linearizable sampled data nonlinear systems. ... more This paper solves the tracking problem for feedback linearizable sampled data nonlinear systems. The conversion of a continuous system into its sampled data equivalent has been discussed and the proposed control law has been derived. In classical control theory, high gain observers based feedback control has been adopted for stabilizing a nonlinear system and state estimation to track a varying reference, but it compromises the main design purpose. The proposed scheme uses augmented state estimation technique to find the additional compensation to be applied at input channel to minimize the tracking error. The results are shown through an illustrative example of an inverted pendulum system that verifies the effectiveness of the proposed scheme.

Modelling for Orientation control of a Drill Machine belonging to a class of under actuated syste... more Modelling for Orientation control of a Drill Machine belonging to a class of under actuated system is presented. The orientation control along x-axis and y-axis of the drill machine is achieved through a single pair of electromagnetic poles. Based on the concept of pulse width modulation a controlling signal for the actuators which caters for all practical limitations of the system is generated. The derived discrete time equivalent model overcomes the practical limitation of control techniques used for such class of systems. It also opens a new dimension especially for under-actuated and non-linear systems which are otherwise difficult rather impossible through orthodox control schemes. A closed form based on discrete time equivalent model supported by simulation results will be helpful in designing overall feedback control for the orientation of the system.

2016 IEEE Asia-Pacific Conference on Applied Electromagnetics (APACE), 2016

Signal processing algorithms are widely used in various applications to find position, range and ... more Signal processing algorithms are widely used in various applications to find position, range and velocity of moving objects. Signal processor part of radar has to perform heavy computations. The time required to localize the target is also critical for surveillance. When target is approaching the radar, detection needs to be faster. A radar signal processor is proposed which is capable of finding range and Doppler with variable processing times for two set of target ranges. The proposed algorithm saves processing time for short range set by reducing the computations involved in FFT stage of conventional two dimensional algorithm. For longer range set, the conventional two dimensional algorithm is used for achieving higher processing gain. It is shown that the modified approach saves much time as compared to the conventional algorithm. The proposed algorithm with reduced processing time can also be useful for long range set if high gain transmitter or better LNA is used at the receiv...

Pakistan Journal of Engineering and Applied Sciences, 2016

A pulse width modulation (PWM) approach based on the discrete equivalent model of an under actuat... more A pulse width modulation (PWM) approach based on the discrete equivalent model of an under actuated spinning body is proposed. The presented work is a sequel to the earlier work done by the authors for the orientation control of the drill machine. The constraint is an actuating signal of fixed amplitude with adjustable pulse width. A novel approach based on error minimization is developed. The optimized values of pulse width and phase of the control input are estimated to generate the actuating signal. The problems of local minima and non-causality were also addressed through proposed technique. The simulations are included to compare proposed techniques with the earlier developed techniques for similar systems. The performance is also shown under both nominal and parameter variations.

Mehran University Research Journal of Engineering and Technology, 2017

The localization of targets has been presented in this article. DOA (Direction of Arrival) is an ... more The localization of targets has been presented in this article. DOA (Direction of Arrival) is an important parameter to be determined by radar. The MLE (Maximum Likelihood Estimator) has been widely used to accurately and efficiently estimate the DOAs of multiple targets. The targets at different ranges result in a variation in amplitude of the received signals, so an MLE estimator has to operate at all ranges. For accurate results of DOA, the complex amplitudes of multiple targets should not be much different and also the prior information of Doppler and number of targets is required. In this paper, an approach is proposed which uses the classical 2D algorithm to estimate range, Doppler and number of targets and then FDA (Frequency Diversity Array) is used to focus power in a particular range. As a result, the MLE can get data from a particular range cell where all targets have almost same amplitude and thus MLE can accurately estimate the DOAs of multiple targets. Simulations and results have confirmed the effectiveness of proposed approach.

IEEE Access, 2018

In this paper, a novel continuous sampled-data observer for linear time-varying systems is presen... more In this paper, a novel continuous sampled-data observer for linear time-varying systems is presented. The proposed observer is based on two different impulsive observers. The state estimates of these impulsive observers are fused in a manner such that continuous state estimation is achieved. Another significant contribution is comprehensive stability analysis of the proposed observer. The analysis establishes conditions that guarantee exponential convergence of observers. Contrary to the common understanding, it is revealed that the convergence of associated discrete-time equation for impulsive observers is not a sufficient condition for overall convergence. Contributions are illustrated by simulations. INDEX TERMS Sampled-data, linear time varying system, impulsive observer.

2016 Chinese Control and Decision Conference (CCDC), 2016

This paper tackles the problem of impulsive observer design for the class of linear time invarian... more This paper tackles the problem of impulsive observer design for the class of linear time invariant system with sampled outputs. The proposed design approach includes continuous-time evolution and discrete jumps at specified time instants. The resulting observer is capable to track the system states in a predefined finite time. The estimation error is shown to be uniformly exponentially stable for any applicable convergence time selected under non-pathological sampling. The performance of this scheme is illustrated with an example to show the convergence behavior and its applicability.

2015 6th International Conference on Modeling, Simulation, and Applied Optimization (ICMSAO), 2015

To have complete information about a target which is detected in RADAR requires its range, veloci... more To have complete information about a target which is detected in RADAR requires its range, velocity/Doppler and Direction of arrival information. RADAR capable of finding all these 3 characteristics of targets can be connected with a network so that targets can be tracked and destroyed using the information. This paper presents Modeling and Simulation results of a 3-D RADAR.

2015 12th International Bhurban Conference on Applied Sciences and Technology (IBCAST), 2015

Robust controller design in presence of disturbance and system parameter uncertainties has been a... more Robust controller design in presence of disturbance and system parameter uncertainties has been a challenging task. In this paper attitude control of ECP 750 Gyroscope in presence of uncertainties is solved using LMI based multi objective state feedback H2 /H∞ controller. The attitude control problem addressed here resembles the formulation of polytopic model of MIMO gyroscope model to cater the parameter uncertainty and subsequent robust controller design using LMI framework is novelty of this work. MATLAB simulation results show better robust attitude control and disturbance rejection.

Proceedings of the Eighth International Symposium on Signal Processing and Its Applications, 2005.

This paper investigates the ability of state space least mean square (SSLMS) algorithm to track a... more This paper investigates the ability of state space least mean square (SSLMS) algorithm to track a chirped signal buried in additive white Gaussian noise. The signal is a sinusoid whose frequency is drifting at a constant rate. After incorporating second order linear time varying state space model of the chirped sinusoid, SSLMS exhibits superior tracking performance over standard LMS & RLS and their known variants. The step size parameter plays an important role in this context. For various values of step size parameter, time average auto-correlation function (ACF) of prediction error is evaluated when responding to chirped signal. Whiteness of prediction error verifies excellent tracking by SSLMS.

2013 IEEE International Conference on Smart Instrumentation, Measurement and Applications (ICSIMA), 2013

A sampled-data regulation problem for a class of continuous time varying systems is presented. Th... more A sampled-data regulation problem for a class of continuous time varying systems is presented. The main constraint is the availability of only the samples of the output for measurement. The particular focus is on such linear time varying systems that can be transformed into linear time invariant systems through sinusoidal transformation. This converts the problem of tracking a constant signal into a sinusoidal signal. Typical to the sampled-data control problems, the control input is generated by a discrete controller along with a discrete observer for state and disturbance estimation. A realizable reconstruction filter, which is a reduced order specialized generalized hold device, connects the discrete controller with the continuous input of the system. The resultant linear time invariant system along with the realizable reconstruction filter is thus presented as a linear impulsive system. The rest of the problem is similar to the classical regulator theory. As an example the control of gyroscope in both perturbed and unperturbed scenarios is presented.

Robotica, 2014

SUMMARYThis paper proposes a solution to the sampled-data regulation problem for feedback lineari... more SUMMARYThis paper proposes a solution to the sampled-data regulation problem for feedback linearizable n-link robotic manipulators. The prime focus is on the development and stability analysis of the proposed control scheme in the presence of model uncertainties and external disturbances. A major constraint is the availability of sampled measurements of output signal. This leads to designing an impulsive observer for feedback linearization. The discrete-time control input is mapped into its continuous-time counterpart using a realizable reconstruction filter (RRF). The underlying control scheme relies on the sampled-data regulator theory based on the discrete-time equivalence of the plant and RRF modeled as impulsive system. This method leads to controller/observer design in discrete time. The working of the entire scheme is dependent on the stability of impulsive observer; hence a Lyapunov-based stability analysis is also included to ensure the stability of a closed-loop system. Th...

2011 9th IEEE International Conference on ASIC, 2011

A realizable reconstruction filter is presented. Since the standard reconstruction filters are no... more A realizable reconstruction filter is presented. Since the standard reconstruction filters are not realizable, our aim is to produce a reconstruction filter as an impulsive system that contains the dynamics of the reference signal. The proposed design is a memory less system and is able to overcome the intersampling behavior when applied in the closed loop system. As compared to other techniques such as generalized sampled data hold devices being used this design does not require the input and output of the reconstruction filter to be of different dimensions.

International Journal of Computer Theory and Engineering, 2012

In this paper output regulation problem for sampled-data systems with constant exogenous signals ... more In this paper output regulation problem for sampled-data systems with constant exogenous signals is considered. A discrete output feedback controller is designed under the assumption that the regulator equation in discrete-time has a solution. Discretization of the plant and exosystem is carried out by zero order hold equivalence. The goal is to design the complete controller/observer in discrete domain. As an application magnetic levitation is discussed. The simulation results along with the comparison with the continuous-time controller show the effectiveness of the proposed controller.