International Journal of Electrical Engineering and Applied Sciences (IJEEAS), 2020
Mobile Communication is the use of technology that allows us to communicate with others in variou... more Mobile Communication is the use of technology that allows us to communicate with others in various locations without the use of any physical connection. The mobile communication system involves a large coverage area that serves a large geographical area. Due to the enormous growth of mobile telephone users, the limited number of channels available in the regions is unable to fulfill the user demand calls and this leads to the channel assignment problem. To solve this problem, efficient channels reuse or allocation policy is needed to optimize the uses of channels with low channels interference in the regions. To have the efficient channel allocation, one of the solutions is to fully optimize utilization of all channels. This project introduces channel assignment with Channel Borrowing Scheme. This scheme allows borrowing of free or unused channels from neighboring or adjacent cells to fulfil the demand calls. Next, the interference occurs in the cells is optimized as the objective f...
International Journal of Intelligent Engineering and Systems, 2021
Interference minimization in cellular network has and will always be top priority, whether in cur... more Interference minimization in cellular network has and will always be top priority, whether in current or future generation of cellular technology. Therefore, cellular channel assignment problem (CAP) requires continuous study and research. This paper presents the study and comparison of Genetic Algorithm (GA) and Particle Swam Optimization (PSO) for CAP in minimizing interference. GA with three variants in term of population selectionroulette wheel selection (RWS), tournament selection (TS) and stochastic universal sampling (SUS) were studied, and then compared with classic PSO. Two CAPs were derived and used to comprehensively evaluate the performances of the PSO and GAs. It was found that GA-TS is ~11% and ~7% faster than GA-RWS and GA-SUS, respectively. Although the difference is small, but it allowed GA-TS to run for few more iterations and eventually achieved better interference minimization. Moreover, it was also found that GA-SUS has less noise and produce a more consistent result. On the other hand, PSO is slower than GA-TS, but has higher potential to converge on smaller minimum value.
Underwater vision is very different with atmospheric vision, in which the former is subjected to ... more Underwater vision is very different with atmospheric vision, in which the former is subjected to a dynamic and visually noisy environment. Absorption of light by the water and rippling waves caused by atmospheric wind are resulting uncertain refraction of light in the underwater environment, thus continuously causing disturbance towards the visual data collected. Therefore, it is always a challenging task to obtain reliable visual data for the control of autonomous underwater vehicle (AUV). In this paper, an AUV was developed and is tasked to perform altitude control and object (poles) tracking control in a swimming pool by merely using a forward-viewing vision camera and a convex mirror. Prior to design and development of control system for the AUV, this paper only focuses on utilizing and optimizing the visual data acquired. The processing process involves only gray-scaled image and without any common color restoration or image enhancement techniques. In fact, the image processing technique implemented for the object tracking control in this paper contains a self-optimizing algorithm, which results improvement on the object detection. The result shows that under similar challenging and dynamic underwater environment, the detection with optimization is 80% more successful than without the optimization.
Uncertainty and non-linearity are two major factors that affect the path tracking performance of ... more Uncertainty and non-linearity are two major factors that affect the path tracking performance of Mecanum-wheeled robot (MWR) in both open-loop and closed-loop control. Conventional control method i.e. via inverse kinematics equation usually involves assumptions and parametric values. This paper proposes a path tracking and optimization method—Linear Angle-to-Gain (LA-G) that is straightforward and intuitive, and capable to achieve decent path tracking performance. The propose method does not require the knowledge of wheel’s radius and MWR’s dimension to perform control. Experiments in path tracking with and without the proposed path optimizer are analyzed and compared in term of integral of absolute error (IAE) and integral of square error (ISE) with respect to reference path. The result shows that the proposed path optimizer successfully improves the tracking of 45° diagonal path under the presence of uncertainties and non-linearity.
Mobile communication is a process of exchanging information by connecting two parties through a w... more Mobile communication is a process of exchanging information by connecting two parties through a wireless network. Practically, mobile communication system involves a large coverage area. However, there has only limited channels to accommodate all the users. Hence, with the increasing number of mobile users recently, it leads to channel assignment problem (CAP). To optimize the channel assignment problem, an initiative is taken to reuse the existing channels in an efficient way with the minimum interference occur in the channels assignment. This helps to optimize the usage of the channel assignment in mobile communication. Tabu Search (TS) technique is implemented to solve the CAP by searching for the global optimum solution with the minimum interference cost value. The reallocated channels are being analyzed on the value of the penalty cost based on the penalty cost function. The optimization of the channels assignment is a process of reducing total channels required as the solution...
Journal of Telecommunication, Electronic and Computer Engineering, 2018
The Electrical and Electronics (E&E) industry continues to be a key driver of Malaysia's Indu... more The Electrical and Electronics (E&E) industry continues to be a key driver of Malaysia's Industrial development and contributes significantly to GDP growth, export earnings, investment, and employment. Malaysia has become a major global manufacturing hub for the E&E industry and four decades and continues to be a preferred E&E investment destination. In order to sustain and stay competitive, the Malaysian semiconductor companies are urged to implement world class maintenance techniques that will improve equipment utilization and thus reducing capital expenditure. Total Productive Maintenance (TPM) is one of the effective maintenance strategies for enhancing the overall equipment effectiveness (OEE) to achieve a significant competitive advantage. The aim of the study is to determine the effectiveness of TPM to improve OEE in the E&E industry. This study used the real time data for two types of die attach equipment models, namely CANON and ESEC. The data was collected from an E&E ...
In this paper, a Continuous Motion Nominal Characteristic Trajectory Following (CM-NCTF) controll... more In this paper, a Continuous Motion Nominal Characteristic Trajectory Following (CM-NCTF) controller is proposed as a practical control approach on a DC driven one mass rotary system. A CM-NCTF controller has simple controller structure and easy design procedures, and it does not require the exact plant model parameters. The CM-NCTF controller is made up of two major parts: a Nominal Characteristic Trajectory (NCT) and a Proportional-Integral (PI) compensator. The NCT is constructed on a phase plane with open loop information of the mechanism, while PI compensator is designed to ensure the mechanism follows the NCT and stops at the origin of the phase plane. The positioning performance of the CM-NCTF controller are evaluated and compared with a PID controller in point-to-point and tracking motion experimentally. The proposed controller achieved at least 36.8 % smaller steady state error than the PID controller, with no presence of overshoot in point-to-point motion. In tracking motio...
The addition of omnidirectional capability and modularization to conveyor systems is an exciting ... more The addition of omnidirectional capability and modularization to conveyor systems is an exciting and trending topic in current conveyor research. The implementation of omnidirectional modular conveyors is foreseen as mandatory in the future of conveyor technologies due to their flexibility and efficiency. In this paper, an E-pattern omniwheeled cellular conveyor (EOCC) is first introduced. Camera and image processing techniques are utilized to achieve a centralized system, which is more robust than conventional decentralized systems. In order for cartons to maneuver across the EOCC, a unique method for activation of the actuators is subsequently designed. Next, the nominal characteristic of the EOCC is analyzed based on the step responses, which then inspire the proposal of four simple controllers, namely the P–P–P–P controller, tTS + P–P–P–P controller, P–P–PD–PD controller, and tTS + P–P–PD–PD controller (P for proportional, D for derivative and tTS for time-shifting), which are u...
TELKOMNIKA (Telecommunication Computing Electronics and Control), 2020
Wireless sensor network (WSN) consists of distributed nodes deployed for monitoring the physical ... more Wireless sensor network (WSN) consists of distributed nodes deployed for monitoring the physical conditions and organizing collected data at the central control unit. Power consumption is the challenges in WSN as the network consists of wireless sensor nodes becomes denser. By utilizing WSN and visible light technology, a simple health monitoring system design can be approached that are smaller in size, faster and lower power consumption. This work focuses on design a low power optical wake-up receiver to reduce the energy consumption of each node in WSN. A wake-up receiver is designed to be always-on for detecting incoming signal and switches on the stand by protocol controller and WSN network for data transmission process. The characteristic of optical transmission and functional circuit of a wake-up receiver has been investigated. A low power optical wake-up receiver has been designed in 180nm Silterra CMOS process technology. The proposed wake-up receiver consumes only 443pW in standby mode and 1.89nW in active mode. The proposed optical wake-up receiver drastically reduces the power consumption by more than one third compared to other wake-up receivers which could be a milestone in the medical field if successfully conducted.
Malaysian Journal of Fundamental and Applied Sciences, 2017
Geophone (model SM-24) pertaining its performance to detect surface wave at Free Wave Generator i... more Geophone (model SM-24) pertaining its performance to detect surface wave at Free Wave Generator is analyzed. Sensitivity studies have been conducted to model the physical disadvantage such as spring suspension and magnetic field in geophone. From mathematical model of the ring permanent magnet, applying “superposition” has suggested a solution: an external resistor across its output terminal to amplify the exhibited linear damping behavior. Geophone with 60%, and 75% damping ratio are designed and built and the results show that 75% damping provide highest sensitivity. Analytic expression of vertical component of magnetic field shows that the damping ratio can be increased physically by increasing the radius of the magnetic field, however, by modifying the SM-24 damping ratio, similar outcome can be obtained.
In an environment of intense global competition, both creative and proven strategies need to be c... more In an environment of intense global competition, both creative and proven strategies need to be considered in order to bring about the effectiveness and efficiency in manufacturing operation. Total Productive Maintenance (TPM) is one of the effective maintenance strategy in enhancing the equipment effectiveness and to achieve a significant competitive advantage. This research paper addresses the impact of three TPM pillars namely planned maintenance (PM), autonomous maintenance (AM) and focused maintenance (FM) on overall equipment effectiveness (OEE) of die attach equipment in the production line of semiconductor industry. The effect of TPM on the OEE is also investigated depending on the equipment types, in where die attach process consist of two models-CANON and ESEC. The primary data was collected from an organization's database and was analysed by SPSS V23. The preliminary results of the analysis showed that the performance of OEE in ESEC is better than the CANON after the ...
This paper presents an intuitively straightforward yet comprehensive approach in developing and c... more This paper presents an intuitively straightforward yet comprehensive approach in developing and controlling a Mecanum-wheeled robot (MWR), with decent path tracking performance by using a simple controller as an end objective. The development starts by implementing two computer ball mice as sensors to realize a simple localization that is immune toward wheel slippage. Then, a linearization method by using open-loop step responses is carried out to linearize the actuations of the robot. Open-loop step response is handy, as it directly portrays the non-linearity of the system, thus achieving effective counteraction. Then, instead of creating a lookup table, polynomial regression is used to generate an equation in which the equation later represents an element of the linearizer. Next, a linear angle-to-gain (LA-G) method is introduced for path tracking control. The method is as easy as just linearly maps the summation of two angles-the angle between immediate and desired positions and the MWR's heading angle, into gains to control the wheels. Unlike the conventional control method which involves inverse kinematics, the LAG method is directly a displacement-controlled approach and does not require the knowledge of parametric values, such as the robot's dimensions and wheel radius. Finally, all the methods are implemented, and the MWR experimentally demonstrates successfully tracking various paths, by merely using proportional controllers.
attention due to the favorable advantages that PMA has to offer such as inherent compliant safety... more attention due to the favorable advantages that PMA has to offer such as inherent compliant safety, compactness, dust-resistant and powerful, especially for rehabilitation application. However, the highly non-linear phenomenon exhibited by PMA poses a challenge in positioning control of the mechanism. Due to the highly nonlinear properties of the PMA system, it is difficult and challengeable to model the system accurately. Many advanced controls have been proposed, however, majority of them requires accurate model parameters for the design and/ or deep understanding of control theory. Therefore, this research aims to highlight a practical and simple control framework capable of providing ameliorated compensation towards the non-linearities in a PMA positioning system. The proposed controller is a combination of a modified PID control incorporated with a model-based feed-forward element. The modified PID control is cascaded with a modeled-nonlinear function and a linearizer that works...
Ball screw mechanisms are widely applied in different industries due to their capability in achie... more Ball screw mechanisms are widely applied in different industries due to their capability in achieving precise positioning performance as well as its long travel range for positioning, travelling and contouring actions. However, this mechanism exhibits nonlinearities in micro movement. In this paper, a disturbance observer and PD controller (PDDO) is proposed in ball screw mechanism to achieve fast and precise positioning performance. A macrodynamic mathematical model of the mechanism is derived. PDDO controller is designed to achieve fast positioning in micro travel range. The robustness of the controller against mass is examined. The experimental results demonstrated that the PDDO controller achieves better performance in fast tracking (3 Hz) with working range at 100 μm, 1 mm and 3 mm as compared to the PID controller. Besides that, the PDDO controller also demonstrated its robustness in the presence of mass changes.
Double-simulated annealing model for mapping of graphs to single-row networks. Loh, Ser Lee and S... more Double-simulated annealing model for mapping of graphs to single-row networks. Loh, Ser Lee and Salleh, Shaharudin and Sarmin, Nor Haniza (2008) Double-simulated annealing model for mapping of graphs to single-row networks. ...
A spanning tree of a connected graph is a tree which consists the set of vertices and some or per... more A spanning tree of a connected graph is a tree which consists the set of vertices and some or perhaps all of the edges from the connected graph. In this paper, a model for spanning tree transformation of connected graphs into single-row networks, namely Spanning Tree of Connected Graph Modeling (STCGM) will be introduced. Path-Growing Tree-Forming algorithm applied with Vertex-Prioritized is contained in the model to produce the spanning tree from the connected graph. Paths are produced by Path-Growing and they are combined into a spanning tree by Tree-Forming. The spanning tree that is produced from the connected graph is then transformed into single-row network using Tree Sequence Modeling (TSM). Finally, the single-row routing problem is solved using a method called Enhanced Simulated Annealing for Single-Row Routing (ESSR).
The Malaysia Renewable Energy Act 2011 has been enacted and feed-in tariff scheme is introduced. ... more The Malaysia Renewable Energy Act 2011 has been enacted and feed-in tariff scheme is introduced. It is expected that photovoltaic (PV) connection may increase in the future. The increasing number of distributed generation connected to the distribution grid may pose great challenge to the operation of distribution networks. However, it is expensive and not cost-effective for TNB to collect all of the network samples for distributed generation scenarios analysis due to the sheer amount of low-voltage distribution network samples. Given the advancement in Geographical Information System (GIS) such as the freely available Google map, it gives an excellent opportunity to exploit the existing GIS system for automatic low voltage network topology generation. The main objective of this research is to generate the network topology of road layer from a map provided by GIS into a connected graph and to produce base case from the resulting network to analyze the impact of photovoltaic (PV). Som...
Electric vehicle (EV) is a new and uprising technology in the transportation and power sector tha... more Electric vehicle (EV) is a new and uprising technology in the transportation and power sector that benefits the economy and environment. This study presents a comprehensive review of electric vehicle technology and its associated equipment, such as battery charger and charging station. An introduction is made on the residential charging type of electric vehicles in terms of charging time, size of battery and power of charger. The influence of electric vehicle charging on utility distribution system in terms of voltage and thermal limits are investigated in this paper. The current power system may not able to support the EV charging loads. The usage of electric vehicles, customer power consumption behavior and the distribution of electric vehicle used in a residential area may affect its power system structure. To study the influence of EV charging in a power distribution system, analysis were conducted based on these three factors. Firstly, the new network will be simulated using al...
International Journal of Electrical Engineering and Applied Sciences (IJEEAS), 2020
Mobile Communication is the use of technology that allows us to communicate with others in variou... more Mobile Communication is the use of technology that allows us to communicate with others in various locations without the use of any physical connection. The mobile communication system involves a large coverage area that serves a large geographical area. Due to the enormous growth of mobile telephone users, the limited number of channels available in the regions is unable to fulfill the user demand calls and this leads to the channel assignment problem. To solve this problem, efficient channels reuse or allocation policy is needed to optimize the uses of channels with low channels interference in the regions. To have the efficient channel allocation, one of the solutions is to fully optimize utilization of all channels. This project introduces channel assignment with Channel Borrowing Scheme. This scheme allows borrowing of free or unused channels from neighboring or adjacent cells to fulfil the demand calls. Next, the interference occurs in the cells is optimized as the objective f...
International Journal of Intelligent Engineering and Systems, 2021
Interference minimization in cellular network has and will always be top priority, whether in cur... more Interference minimization in cellular network has and will always be top priority, whether in current or future generation of cellular technology. Therefore, cellular channel assignment problem (CAP) requires continuous study and research. This paper presents the study and comparison of Genetic Algorithm (GA) and Particle Swam Optimization (PSO) for CAP in minimizing interference. GA with three variants in term of population selectionroulette wheel selection (RWS), tournament selection (TS) and stochastic universal sampling (SUS) were studied, and then compared with classic PSO. Two CAPs were derived and used to comprehensively evaluate the performances of the PSO and GAs. It was found that GA-TS is ~11% and ~7% faster than GA-RWS and GA-SUS, respectively. Although the difference is small, but it allowed GA-TS to run for few more iterations and eventually achieved better interference minimization. Moreover, it was also found that GA-SUS has less noise and produce a more consistent result. On the other hand, PSO is slower than GA-TS, but has higher potential to converge on smaller minimum value.
Underwater vision is very different with atmospheric vision, in which the former is subjected to ... more Underwater vision is very different with atmospheric vision, in which the former is subjected to a dynamic and visually noisy environment. Absorption of light by the water and rippling waves caused by atmospheric wind are resulting uncertain refraction of light in the underwater environment, thus continuously causing disturbance towards the visual data collected. Therefore, it is always a challenging task to obtain reliable visual data for the control of autonomous underwater vehicle (AUV). In this paper, an AUV was developed and is tasked to perform altitude control and object (poles) tracking control in a swimming pool by merely using a forward-viewing vision camera and a convex mirror. Prior to design and development of control system for the AUV, this paper only focuses on utilizing and optimizing the visual data acquired. The processing process involves only gray-scaled image and without any common color restoration or image enhancement techniques. In fact, the image processing technique implemented for the object tracking control in this paper contains a self-optimizing algorithm, which results improvement on the object detection. The result shows that under similar challenging and dynamic underwater environment, the detection with optimization is 80% more successful than without the optimization.
Uncertainty and non-linearity are two major factors that affect the path tracking performance of ... more Uncertainty and non-linearity are two major factors that affect the path tracking performance of Mecanum-wheeled robot (MWR) in both open-loop and closed-loop control. Conventional control method i.e. via inverse kinematics equation usually involves assumptions and parametric values. This paper proposes a path tracking and optimization method—Linear Angle-to-Gain (LA-G) that is straightforward and intuitive, and capable to achieve decent path tracking performance. The propose method does not require the knowledge of wheel’s radius and MWR’s dimension to perform control. Experiments in path tracking with and without the proposed path optimizer are analyzed and compared in term of integral of absolute error (IAE) and integral of square error (ISE) with respect to reference path. The result shows that the proposed path optimizer successfully improves the tracking of 45° diagonal path under the presence of uncertainties and non-linearity.
Mobile communication is a process of exchanging information by connecting two parties through a w... more Mobile communication is a process of exchanging information by connecting two parties through a wireless network. Practically, mobile communication system involves a large coverage area. However, there has only limited channels to accommodate all the users. Hence, with the increasing number of mobile users recently, it leads to channel assignment problem (CAP). To optimize the channel assignment problem, an initiative is taken to reuse the existing channels in an efficient way with the minimum interference occur in the channels assignment. This helps to optimize the usage of the channel assignment in mobile communication. Tabu Search (TS) technique is implemented to solve the CAP by searching for the global optimum solution with the minimum interference cost value. The reallocated channels are being analyzed on the value of the penalty cost based on the penalty cost function. The optimization of the channels assignment is a process of reducing total channels required as the solution...
Journal of Telecommunication, Electronic and Computer Engineering, 2018
The Electrical and Electronics (E&E) industry continues to be a key driver of Malaysia's Indu... more The Electrical and Electronics (E&E) industry continues to be a key driver of Malaysia's Industrial development and contributes significantly to GDP growth, export earnings, investment, and employment. Malaysia has become a major global manufacturing hub for the E&E industry and four decades and continues to be a preferred E&E investment destination. In order to sustain and stay competitive, the Malaysian semiconductor companies are urged to implement world class maintenance techniques that will improve equipment utilization and thus reducing capital expenditure. Total Productive Maintenance (TPM) is one of the effective maintenance strategies for enhancing the overall equipment effectiveness (OEE) to achieve a significant competitive advantage. The aim of the study is to determine the effectiveness of TPM to improve OEE in the E&E industry. This study used the real time data for two types of die attach equipment models, namely CANON and ESEC. The data was collected from an E&E ...
In this paper, a Continuous Motion Nominal Characteristic Trajectory Following (CM-NCTF) controll... more In this paper, a Continuous Motion Nominal Characteristic Trajectory Following (CM-NCTF) controller is proposed as a practical control approach on a DC driven one mass rotary system. A CM-NCTF controller has simple controller structure and easy design procedures, and it does not require the exact plant model parameters. The CM-NCTF controller is made up of two major parts: a Nominal Characteristic Trajectory (NCT) and a Proportional-Integral (PI) compensator. The NCT is constructed on a phase plane with open loop information of the mechanism, while PI compensator is designed to ensure the mechanism follows the NCT and stops at the origin of the phase plane. The positioning performance of the CM-NCTF controller are evaluated and compared with a PID controller in point-to-point and tracking motion experimentally. The proposed controller achieved at least 36.8 % smaller steady state error than the PID controller, with no presence of overshoot in point-to-point motion. In tracking motio...
The addition of omnidirectional capability and modularization to conveyor systems is an exciting ... more The addition of omnidirectional capability and modularization to conveyor systems is an exciting and trending topic in current conveyor research. The implementation of omnidirectional modular conveyors is foreseen as mandatory in the future of conveyor technologies due to their flexibility and efficiency. In this paper, an E-pattern omniwheeled cellular conveyor (EOCC) is first introduced. Camera and image processing techniques are utilized to achieve a centralized system, which is more robust than conventional decentralized systems. In order for cartons to maneuver across the EOCC, a unique method for activation of the actuators is subsequently designed. Next, the nominal characteristic of the EOCC is analyzed based on the step responses, which then inspire the proposal of four simple controllers, namely the P–P–P–P controller, tTS + P–P–P–P controller, P–P–PD–PD controller, and tTS + P–P–PD–PD controller (P for proportional, D for derivative and tTS for time-shifting), which are u...
TELKOMNIKA (Telecommunication Computing Electronics and Control), 2020
Wireless sensor network (WSN) consists of distributed nodes deployed for monitoring the physical ... more Wireless sensor network (WSN) consists of distributed nodes deployed for monitoring the physical conditions and organizing collected data at the central control unit. Power consumption is the challenges in WSN as the network consists of wireless sensor nodes becomes denser. By utilizing WSN and visible light technology, a simple health monitoring system design can be approached that are smaller in size, faster and lower power consumption. This work focuses on design a low power optical wake-up receiver to reduce the energy consumption of each node in WSN. A wake-up receiver is designed to be always-on for detecting incoming signal and switches on the stand by protocol controller and WSN network for data transmission process. The characteristic of optical transmission and functional circuit of a wake-up receiver has been investigated. A low power optical wake-up receiver has been designed in 180nm Silterra CMOS process technology. The proposed wake-up receiver consumes only 443pW in standby mode and 1.89nW in active mode. The proposed optical wake-up receiver drastically reduces the power consumption by more than one third compared to other wake-up receivers which could be a milestone in the medical field if successfully conducted.
Malaysian Journal of Fundamental and Applied Sciences, 2017
Geophone (model SM-24) pertaining its performance to detect surface wave at Free Wave Generator i... more Geophone (model SM-24) pertaining its performance to detect surface wave at Free Wave Generator is analyzed. Sensitivity studies have been conducted to model the physical disadvantage such as spring suspension and magnetic field in geophone. From mathematical model of the ring permanent magnet, applying “superposition” has suggested a solution: an external resistor across its output terminal to amplify the exhibited linear damping behavior. Geophone with 60%, and 75% damping ratio are designed and built and the results show that 75% damping provide highest sensitivity. Analytic expression of vertical component of magnetic field shows that the damping ratio can be increased physically by increasing the radius of the magnetic field, however, by modifying the SM-24 damping ratio, similar outcome can be obtained.
In an environment of intense global competition, both creative and proven strategies need to be c... more In an environment of intense global competition, both creative and proven strategies need to be considered in order to bring about the effectiveness and efficiency in manufacturing operation. Total Productive Maintenance (TPM) is one of the effective maintenance strategy in enhancing the equipment effectiveness and to achieve a significant competitive advantage. This research paper addresses the impact of three TPM pillars namely planned maintenance (PM), autonomous maintenance (AM) and focused maintenance (FM) on overall equipment effectiveness (OEE) of die attach equipment in the production line of semiconductor industry. The effect of TPM on the OEE is also investigated depending on the equipment types, in where die attach process consist of two models-CANON and ESEC. The primary data was collected from an organization's database and was analysed by SPSS V23. The preliminary results of the analysis showed that the performance of OEE in ESEC is better than the CANON after the ...
This paper presents an intuitively straightforward yet comprehensive approach in developing and c... more This paper presents an intuitively straightforward yet comprehensive approach in developing and controlling a Mecanum-wheeled robot (MWR), with decent path tracking performance by using a simple controller as an end objective. The development starts by implementing two computer ball mice as sensors to realize a simple localization that is immune toward wheel slippage. Then, a linearization method by using open-loop step responses is carried out to linearize the actuations of the robot. Open-loop step response is handy, as it directly portrays the non-linearity of the system, thus achieving effective counteraction. Then, instead of creating a lookup table, polynomial regression is used to generate an equation in which the equation later represents an element of the linearizer. Next, a linear angle-to-gain (LA-G) method is introduced for path tracking control. The method is as easy as just linearly maps the summation of two angles-the angle between immediate and desired positions and the MWR's heading angle, into gains to control the wheels. Unlike the conventional control method which involves inverse kinematics, the LAG method is directly a displacement-controlled approach and does not require the knowledge of parametric values, such as the robot's dimensions and wheel radius. Finally, all the methods are implemented, and the MWR experimentally demonstrates successfully tracking various paths, by merely using proportional controllers.
attention due to the favorable advantages that PMA has to offer such as inherent compliant safety... more attention due to the favorable advantages that PMA has to offer such as inherent compliant safety, compactness, dust-resistant and powerful, especially for rehabilitation application. However, the highly non-linear phenomenon exhibited by PMA poses a challenge in positioning control of the mechanism. Due to the highly nonlinear properties of the PMA system, it is difficult and challengeable to model the system accurately. Many advanced controls have been proposed, however, majority of them requires accurate model parameters for the design and/ or deep understanding of control theory. Therefore, this research aims to highlight a practical and simple control framework capable of providing ameliorated compensation towards the non-linearities in a PMA positioning system. The proposed controller is a combination of a modified PID control incorporated with a model-based feed-forward element. The modified PID control is cascaded with a modeled-nonlinear function and a linearizer that works...
Ball screw mechanisms are widely applied in different industries due to their capability in achie... more Ball screw mechanisms are widely applied in different industries due to their capability in achieving precise positioning performance as well as its long travel range for positioning, travelling and contouring actions. However, this mechanism exhibits nonlinearities in micro movement. In this paper, a disturbance observer and PD controller (PDDO) is proposed in ball screw mechanism to achieve fast and precise positioning performance. A macrodynamic mathematical model of the mechanism is derived. PDDO controller is designed to achieve fast positioning in micro travel range. The robustness of the controller against mass is examined. The experimental results demonstrated that the PDDO controller achieves better performance in fast tracking (3 Hz) with working range at 100 μm, 1 mm and 3 mm as compared to the PID controller. Besides that, the PDDO controller also demonstrated its robustness in the presence of mass changes.
Double-simulated annealing model for mapping of graphs to single-row networks. Loh, Ser Lee and S... more Double-simulated annealing model for mapping of graphs to single-row networks. Loh, Ser Lee and Salleh, Shaharudin and Sarmin, Nor Haniza (2008) Double-simulated annealing model for mapping of graphs to single-row networks. ...
A spanning tree of a connected graph is a tree which consists the set of vertices and some or per... more A spanning tree of a connected graph is a tree which consists the set of vertices and some or perhaps all of the edges from the connected graph. In this paper, a model for spanning tree transformation of connected graphs into single-row networks, namely Spanning Tree of Connected Graph Modeling (STCGM) will be introduced. Path-Growing Tree-Forming algorithm applied with Vertex-Prioritized is contained in the model to produce the spanning tree from the connected graph. Paths are produced by Path-Growing and they are combined into a spanning tree by Tree-Forming. The spanning tree that is produced from the connected graph is then transformed into single-row network using Tree Sequence Modeling (TSM). Finally, the single-row routing problem is solved using a method called Enhanced Simulated Annealing for Single-Row Routing (ESSR).
The Malaysia Renewable Energy Act 2011 has been enacted and feed-in tariff scheme is introduced. ... more The Malaysia Renewable Energy Act 2011 has been enacted and feed-in tariff scheme is introduced. It is expected that photovoltaic (PV) connection may increase in the future. The increasing number of distributed generation connected to the distribution grid may pose great challenge to the operation of distribution networks. However, it is expensive and not cost-effective for TNB to collect all of the network samples for distributed generation scenarios analysis due to the sheer amount of low-voltage distribution network samples. Given the advancement in Geographical Information System (GIS) such as the freely available Google map, it gives an excellent opportunity to exploit the existing GIS system for automatic low voltage network topology generation. The main objective of this research is to generate the network topology of road layer from a map provided by GIS into a connected graph and to produce base case from the resulting network to analyze the impact of photovoltaic (PV). Som...
Electric vehicle (EV) is a new and uprising technology in the transportation and power sector tha... more Electric vehicle (EV) is a new and uprising technology in the transportation and power sector that benefits the economy and environment. This study presents a comprehensive review of electric vehicle technology and its associated equipment, such as battery charger and charging station. An introduction is made on the residential charging type of electric vehicles in terms of charging time, size of battery and power of charger. The influence of electric vehicle charging on utility distribution system in terms of voltage and thermal limits are investigated in this paper. The current power system may not able to support the EV charging loads. The usage of electric vehicles, customer power consumption behavior and the distribution of electric vehicle used in a residential area may affect its power system structure. To study the influence of EV charging in a power distribution system, analysis were conducted based on these three factors. Firstly, the new network will be simulated using al...
Uploads
Papers by Ser Lee Loh