Mudasir Ahmed Memon | University of Sindh, Pakistan (original) (raw)
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Papers by Mudasir Ahmed Memon
Computer generated animation has become extremely popular in current era involved not only in mov... more Computer generated animation has become extremely popular in current era involved not only in movies and games, but mainstream television, education, scientific visualizations, Sports are but few noteworthy areas of its application. Even though majorly two types of animation techniques are used in the general industry; namely key-frame and motion capture, there are various other techniques of generating autonomous animation. In this survey paper we discuss the major techniques and approaches towards procedurally generating autonomous animation of Quadruped characters in specific. Initially we discuss various techniques used in generating skeletons and creating a character rig for quadrupeds. The various animation techniques are then discussed from footprint generation to data driven methods and finally physics and dynamics based approached and algorithms. All these methodologies tend to provide best possible solution for solving the problem of generating involuntary and autonomous animation of quadruped characters. In the end, a more suitable hybrid technique is proposed which will be more practically feasible and user friendly so it can be easily implemented.
Uninterruptible power supplies (UPSs) are widely used to deliver reliable and high quality power ... more Uninterruptible power supplies (UPSs) are widely used to deliver reliable and high quality power to critical loads under all grid conditions. This paper proposes a high-frequency isolated online UPS system for low power applications. The proposed UPS consists of a single-stage AC-DC converter, boost DC-DC converter, and an inverter. The single-stage AC-DC converter provides galvanic isolation, input power factor correction, and continuous conduction of both input and output current. The low battery bank voltage is stepped up to high dc-link voltage by employing a high voltage gain boost converter, thus allows the reduction of battery bank to only 24 V parallel connected batteries. Operating batteries in parallel improves the battery performance and resolves the issues related to conventional battery banks that arrange the batteries in series combination. The inverter provides regulated output voltage to the load. A new cascaded slide mode (SM) and proportional-resonant (PR) control for the inverter has been proposed, which regulates the output voltage for both linear and non-linear loads. The controller shows excellent performance during load transients and step changes. Besides, the controller for boost converter and AC-DC converter is presented. Operating principle and experimental results of 1 kVA laboratory setup have been presented for the validation of proposed system.
A B S T R A C T Observing present scarcity of fossil fuel and emissions of greenhouse gases, elec... more A B S T R A C T Observing present scarcity of fossil fuel and emissions of greenhouse gases, electricity generated from Renewable Energy (RE) sources turns out to be the best alternative for generating the power. In RE system, the inverter is normally used to condition the DC power into AC to meet the requirements of load and transmission system. The inverter offers myriad benefits; however, the presence of harmonics (particularly low-order) in the output voltage affects the efficiency and performance of inverter, causes switching losses and decreases the lifetime of the system. In last three decades, significant research has been done to develop the efficient control technique for eliminating the unwanted harmonics. The preliminary review of existing control techniques revealed that the selective harmonic elimination pulse-width modulation (SHEPWM) is more proficient to eliminate the low-order harmonics. However, non-linear transcendental equations used in this technique pose a challenge to solve particularly for calculus-based methods. With the advent of powerful and low-cost computers, bio-inspired intelligent algorithms (BIAs) seem to be a better approach for solving these complex equations. This review paper presents the detailed principle operation of nine well-known BIAs and discusses their application in inverters for harmonic elimination (HE). Moreover, different objective functions are also discussed in this paper which is used by the researchers for HE. Additionally, the performance of five renowned BIAs, namely, Imperialist Competitive Algorithm, Particle Swarm Optimization, Differential Evolution, Bee Algorithm and Genetic Algorithm is critically evaluated. Their performance is analyzed in terms of accuracy, computational complexity, convergence speed, and a number of control parameters. The conclusion has been made on the basis of information extracted from the literature and evaluation results with future recommendations. This single paper covers all the essential information regarding HE in inverters, which will help researchers to design the efficient RE conversion system.
This paper presents a simple and effective approach for mobile robot that detects and avoids dens... more This paper presents a simple and effective approach for mobile robot that detects and avoids densely populated and randomly distributed same size circular shaped static obstacles. The PSO (Particle Swarm Optimization) algorithm is implemented in the proposed technique to determine the optimum route of a robot from source to destination point until any obstacle is detected on its path. Once any obstacle is detected over the optimized path, the obstacle avoidance is done by moving robot towards the nearest safe point around the obstacle’s boundary which is pre-defined and calculated. Furthermore, proposed technique calculates the next point around the obstacle’s boundary which is nearest to the predefined target. For finding the effectiveness, PSO and GA (Genetic Algorithm) is applied and simulated on three different cases. Each case has variation in the location of starting point and goal. Finally, simulation results of all three cases are compared in-terms of Number of Iterations, Path Length and Execution Time. In result, the PSO performs better than GA in all three cases and provides a collision free smooth path in simulated environment.
Computer generated animation has become extremely popular in current era involved not only in mov... more Computer generated animation has become extremely popular in current era involved not only in movies and games, but mainstream television, education, scientific visualizations, Sports are but few noteworthy areas of its application. Even though majorly two types of animation techniques are used in the general industry; namely key-frame and motion capture, there are various other techniques of generating autonomous animation. In this survey paper we discuss the major techniques and approaches towards procedurally generating autonomous animation of Quadruped characters in specific. Initially we discuss various techniques used in generating skeletons and creating a character rig for quadrupeds. The various animation techniques are then discussed from footprint generation to data driven methods and finally physics and dynamics based approached and algorithms. All these methodologies tend to provide best possible solution for solving the problem of generating involuntary and autonomous animation of quadruped characters. In the end, a more suitable hybrid technique is proposed which will be more practically feasible and user friendly so it can be easily implemented.
Uninterruptible power supplies (UPSs) are widely used to deliver reliable and high quality power ... more Uninterruptible power supplies (UPSs) are widely used to deliver reliable and high quality power to critical loads under all grid conditions. This paper proposes a high-frequency isolated online UPS system for low power applications. The proposed UPS consists of a single-stage AC-DC converter, boost DC-DC converter, and an inverter. The single-stage AC-DC converter provides galvanic isolation, input power factor correction, and continuous conduction of both input and output current. The low battery bank voltage is stepped up to high dc-link voltage by employing a high voltage gain boost converter, thus allows the reduction of battery bank to only 24 V parallel connected batteries. Operating batteries in parallel improves the battery performance and resolves the issues related to conventional battery banks that arrange the batteries in series combination. The inverter provides regulated output voltage to the load. A new cascaded slide mode (SM) and proportional-resonant (PR) control for the inverter has been proposed, which regulates the output voltage for both linear and non-linear loads. The controller shows excellent performance during load transients and step changes. Besides, the controller for boost converter and AC-DC converter is presented. Operating principle and experimental results of 1 kVA laboratory setup have been presented for the validation of proposed system.
A B S T R A C T Observing present scarcity of fossil fuel and emissions of greenhouse gases, elec... more A B S T R A C T Observing present scarcity of fossil fuel and emissions of greenhouse gases, electricity generated from Renewable Energy (RE) sources turns out to be the best alternative for generating the power. In RE system, the inverter is normally used to condition the DC power into AC to meet the requirements of load and transmission system. The inverter offers myriad benefits; however, the presence of harmonics (particularly low-order) in the output voltage affects the efficiency and performance of inverter, causes switching losses and decreases the lifetime of the system. In last three decades, significant research has been done to develop the efficient control technique for eliminating the unwanted harmonics. The preliminary review of existing control techniques revealed that the selective harmonic elimination pulse-width modulation (SHEPWM) is more proficient to eliminate the low-order harmonics. However, non-linear transcendental equations used in this technique pose a challenge to solve particularly for calculus-based methods. With the advent of powerful and low-cost computers, bio-inspired intelligent algorithms (BIAs) seem to be a better approach for solving these complex equations. This review paper presents the detailed principle operation of nine well-known BIAs and discusses their application in inverters for harmonic elimination (HE). Moreover, different objective functions are also discussed in this paper which is used by the researchers for HE. Additionally, the performance of five renowned BIAs, namely, Imperialist Competitive Algorithm, Particle Swarm Optimization, Differential Evolution, Bee Algorithm and Genetic Algorithm is critically evaluated. Their performance is analyzed in terms of accuracy, computational complexity, convergence speed, and a number of control parameters. The conclusion has been made on the basis of information extracted from the literature and evaluation results with future recommendations. This single paper covers all the essential information regarding HE in inverters, which will help researchers to design the efficient RE conversion system.
This paper presents a simple and effective approach for mobile robot that detects and avoids dens... more This paper presents a simple and effective approach for mobile robot that detects and avoids densely populated and randomly distributed same size circular shaped static obstacles. The PSO (Particle Swarm Optimization) algorithm is implemented in the proposed technique to determine the optimum route of a robot from source to destination point until any obstacle is detected on its path. Once any obstacle is detected over the optimized path, the obstacle avoidance is done by moving robot towards the nearest safe point around the obstacle’s boundary which is pre-defined and calculated. Furthermore, proposed technique calculates the next point around the obstacle’s boundary which is nearest to the predefined target. For finding the effectiveness, PSO and GA (Genetic Algorithm) is applied and simulated on three different cases. Each case has variation in the location of starting point and goal. Finally, simulation results of all three cases are compared in-terms of Number of Iterations, Path Length and Execution Time. In result, the PSO performs better than GA in all three cases and provides a collision free smooth path in simulated environment.