Rizauddin Ramli

Universiti Kebangsaan Malaysia | ukm · Department of Mechanical and Manufacturing Engineering

Deaf and hard-of-hearing individuals use sign language as a means of communication. However, those around them, especially family members like the children of deaf adults, may face communication challenges if they are unfamiliar with sign language. This issue has prompted numerous researchers to conduct studies on sign language translation and reco...

A "Stroke" is a neurological disease due to poor blood flowing to the brain, resulting in body cell death. It is ranked second as the most common cause of death globally. The "World Health Organization" estimates that about 15 million people suffer a stroke annually. Most stroke survivors have gait disorders, and most patients cannot walk without a...

Deaf and hard of hearing people use sign language to communicate. People around mute and deaf people have difficulty communicating with each other if they do not understand sign language. This problem has prompted many researchers to conduct studies on sign language translation. However, there is a lack of compilation of SLR on this topic. Therefor...

A wearable lower-limb rehabilitation exoskeleton functions to fulfill the recovery process of limb functionality and assist physiotherapists. This paper presents an optimized adaptive control system for a wearable lower-limb rehabilitation exoskeleton. The tuning of the controller gains is defined as an optimization problem for a closed-loop contro...

Driver drowsiness is considered as a significant risk factor that impacted to large number of road accidents. This paper presents a vehicle safety system developed using computer vision technique to detect driver drowsiness while driving. Deep learning method, YOLOv2 has been chosen as the artificial intelligence model to detect the percentage of e...

In this paper, we present a modelling, dynamic analysis, and controller tuning comparison for a five-degree-of-freedom (DoF) multi-joint robotic arm based on the Lyapunov-based Adaptive Controller (LAC). In most pick-and-place applications of robotic arms, it is essential to control the end-effector trajectory to reach a precise target position. Th...

The idea of developing a multi-joint rehabilitation robot is to satisfy the demands for recovery of lower limb functionality in hemiplegic impairments and assist the physiotherapists with their therapy plans. This work aims at to implement the Lyapunov Adaptive and Swarm�Fuzzy Logic Control (LASFC) strategy of 4-degree of freedom (4 DoF) Lower Limb...

Due to its ability to remove material quickly while maintaining optimum surface quality, end milling is considered one of the most frequent metal cutting procedures in industry. The present study aimed to investigate the impacts of cutting parameters and tool geometry on milling of Aluminum Alloy 6061-T6 to examine the impact surface roughness by u...

Achieving high performance controller for multi-joints actuators on rehabilitation lower limb exoskele-ton (RLLE) is difficult due to its non-linear characteristics. The controller performance with less tracking error is a key challenge in their controller. Therefore, this paper presents a new particle swarm optimization based initialization of mod...

Driver drowsiness is considered as a significant risk factor that im-pacted to large number of road accidents. This paper presents a vehicle safety system developed using computer vision technique to detect driver drowsiness while driving. Deep learning method, YOLOv2 has been chosen as the artificial intelligence model to detect the percentage of...

Magnetic flux leakage (MFL) is a common method used in Non-Destructive Test (NDT) to identify inner surface crack in thick-walled steel. This paper presents an MFL system for the defect detection of a ferromagnetic material embedded in the steel floor. The system applies a novel I-Kaz method as the kurtosis-based algorithm as a post-statistical ana...

This paper presents Artificial Neural Network (ANN) as an optimization tool in tuning Proportional-Integral-Derivative (PID) controller’s gain of a multi-joints Lower Limb Exoskeleton (LLE) for gait rehabilitation. The interest in wearable post-stroke and spinal cord injury rehabilitation devices such as LLE has been increasing due to the demand fo...

It is necessary to control the movement of a complex multi-joint structure such as a robotic arm in order to reach a target position accurately in various applications. In this paper, a hybrid optimal Genetic-Swarm solution for the Inverse Kinematic (IK) solution of a robotic arm is presented. Each joint is controlled by Proportional-Integral-Deriv...

An adaptive control with a reference model provides a solution for nonlinearity and uncertainty in dynamics characteristics of rehabilitation lower limb exoskeleton (RLLE). Robustness and compliance are two important challenges for employing joint trajectory control in RLLE application. Therefore, this paper presents the development of RLLE hip-kne...

Creativity is very important in the conceptual design stage for mechatronic products. The innovation and development of mechatronic products usually cover different knowledge domains. Traditionally, ideation comes intuitively or logically. However, this depends on the creativity and ideas of the designer. As such, tools; such as Pugh's total design...

Tuning of a proportional-integral-derivative (PID) controller for a complex multi-joint structure, such as an exoskeleton, using conventional methods is difficult and imprecise. In this paper, an optimal PID tuning method for a 3-dimensional model of a lower-limb human exoskeleton in gait training condition is presented. The dynamic equation of the...

This paper presents a comprehensive review of the development of magnetic flux leakage (MFL) applied by the researcher to improve existing methodology and evaluation techniques in MFL sensor development for corrosion detection in Above Storage Tanks (ASTs). MFL plays an important role in Non-Destructive (NDT) testing to detect crack and corrosion i...

The application of hall sensors in Magnetitic Flux Leakage (MFL) has played an important role in Above Storage Tank (AST) on detection of defect caused by corrosion to improve productivity and to avoid catastrophe. The MFL sensor measured magnetic flux distribution in three axes B x , B y and B z. Currently, there are several signal monitoring meth...

Estimating the parameters of a geared DC motor is crucial in terms of its non-linear features. In this paper, parameters of a geared DC motor are estimated genetically. Mathematical model of the DC motor is determined by Kirchhoff’s law and dynamic model of its shafts and gearbox. Parameters of the geared DC motor are initially estimated by MATLAB/...

In this paper, the development of controlling a six Degree of Freedom (DOF) Lower Limb Exoskeleton (LLE) model using the Robot Operating System (ROS) is presented. Moreover, this work proposes a method to analyze kinematic properties and control of the LLE before the prototype. The model of the LLE is described using Extensible Markup Language (XML...

Much focus on managing a supply chain in the event of disruption has been on the financial consequences and the service level impact on the customers. The negative impact caused by the disruption could influence a company’s profit and market share. Nonetheless, the importance of the environmental impact consideration in the supply chain disruption...

Achieving sustainable machining is in demand nowadays and it is in line with the rise of global eco-awareness and rigorous regulations by the authorities to prevent from further damaging the environment and its constituents. One of the sustainable solutions extensively explored over the years is machining with minimum quantity lubrication system. N...

Achieving precise parameters of multi-joints actuators for Hip–Knee Exoskeleton (HKE) is a crucial process due to its non-linear characteristics. In this paper, a Genetic Algorithm (GA) based optimization is used for parameter estimation of the mathematical model for a four-Degree of Freedom (DoF) multi-joint HKE, which is a type of Lower Limb Exos...

Geometrical dimensioning and tolerance (GD&T) are an important element of the industry that uses high-speed rotation. Poor geometrical tolerance (GT) to components will cause the rotor to become unbalanced. Unbalanced rotor and shaft misalignment are the two major sources of vibration in the rotating system. This paper compares geometrical characte...

In this paper, a Proportional-Integral-Derivative (PID) controller tuning scheme by Initialized Model Reference Adaptive Control (IMRAC) for a Lower Limb Exoskeleton (LLE) is presented. Mathematical expression of the LLE structure is determined using Lagrangian and Kirchoff’s equations. The transfer function of the structure based on the physical f...

p>This paper presents a review of state-of-art in the Magnetic Flux Leakage (MFL) sensor technology, which plays an important role in Nondestructive Testing (NDT) to detect crack and corrosion in ferromagnetic material. The demand of more reliable MFL tools and signal acquisition increase as it has a direct impact on structure integrity and can lea...

In this paper, a method of tuning a proportional-integral-derivative controller for a four degree-of-freedom lower limb exoskeleton using hybrid of genetic algorithm and particle swarm optimization is presented. Transfer function of each link of the lower limb exoskeleton acquired from a pendulum model, was used in a closed-loop proportional-integr...

The lower limb exoskeleton (LLE) is a device used to assist paraplegics in regaining their ability to walk. The LLE is capable of providing paraplegics with a better degree of locomotion than a wheelchair. However, in LLE design, size is a critical issue that needs to be considered. The LLE should be small in package, compact, and portable. Therefo...

A combined proactive and reactive approach to deal with disruption in the supply chain (SC) is presented in this paper, where an optimization model that is capable of determining the optimal safety stock level and optimal recovery schedule for a serial two-stage SC system was developed. The system considered in the study consists of a single vendor...

This paper presents some of the earlier studies pertaining of analytical methods for tolerance, its effect and applications in the automotive industry. In today’s automotive and aerospace industries, the tolerance process is crucial in the design phase and product development. In the design process, issues such as matches and limits, geometric an...

This paper presents some of the earlier studies pertaining of analytical methods for tolerance, its effect and applications in the automotive industry. In today's automotive and aerospace industries, the tolerance process is crucial in the design phase and product development. In the design process, issues such as matches and limits, geometric and...

This study presents an uncertain mathematical model for maximizing profit of the defective goods supply chain during uncertain situations by using selection of appropriate suppliers, just-in-time (JIT) logistic philosophy and minimizing total costs including costs of production, shipping, holding, defective goods, scrap goods, shortage in retailers...

Managing highly evolved supply chains and maintaining environmental sustainability at the same time is not easy, especially when it is vulnerable to various disruption risks. In the event of a disruption, the sustainability of a supply chain will be compromised as a consequence of attempting to quickly recover from the disruption with minimal costs...

This paper presents a methodology of using co-simulation to study the dynamic performance analysis of a lower limb exoskeleton (LLE). For patients who suffer permanent spinal cord injury, using the LLE is one of the most effective ways to assist their walking ability compared to the wheelchair. The robustness of the LLE performance is related to th...

This paper aims to identify students' perception of the level of applicability of techniques that have been applied in the process of engineering design idea generation. Various techniques have been developed to facilitate the process of generating ideas. However, in generating engineering design concepts, a special technique involving the applicat...

Reducing machining time in a milling process is one of the important criteria to improve the overall efficiency of the machining process. This paper presents a study on the reduction of machining time, focusing on contour parallel machining to increase the efficiency and performance during the machining process. One method to enhance the performanc...

Research into the development of the lower limb exoskeleton (LLE) has been on-going since the 1960s. Although this field has long been explored, the technological progress has been very slow. Many exoskeletons were stopped in their tracks toward commercialization at the research stage itself. Therefore, this paper is aimed at systematically reviewi...

Design for upgradability is one of the strategies in a remanufacturing process that can help to improve the features of a product in terms of performance and functions. This paper presents a study on the performance evaluation of a product at the engineering metric level for upgrade purpose. A brake caliper was used as a case example in which brake...

Reduction of machining time is significant for increasing the efficiencies of a machining process. It can be minimized by the rise with the cutting speed or decrease the tool path length. This paper presents an optimization method of non-productive tool path length during contour parallel offset machining by minimizing the tool retraction based on...

In today’s competitive market of manufacturing industry, shorter machining time is one of important factor for reducing the manufacturer’s cost. This paper presents the minimisation of machining time of computer numerical control (CNC) by eliminating the uncut region of sharp corner based on contour parallel milling method. Each uncut region at sha...

It is necessary to have an alternative approach in handling end of life vehicle (ELV) other than disposal, due to its adverse impact to the environment. Remanufacturing is the process that can retain the values of used products when they reached the end of their useful life. Product upgradability for multiple lifecycle products (MLPs) is one of the...

Customer focus is essential in ensuring the performance of an organisation including education and training organisations. Customers in the education and training sectors consist of a variety of groups including students, parents, industry, civil society and the relevant authorities. Other than that, the faculty and staff are also internal customer...

Purpose – The purpose of this paper is to give a clear picture of the evidence for small and medium enterprises of what the key factors are affecting the performance of supply chain members (SCMs) and their impact. Design/methodology/approach – The authors conducted a survey of small and medium automotive enterprises. After a comprehensive search...

In machining operations, repositioning the cutting tool requires airtime motion of the cutting tool. Minimizing the airtime motion during pocket machining in mass production is important for increasing the efficiencies of the machining process. This paper presents an optimization of airtime motion during contour parallel offset machining by minimizing...

This study proposed a set of techniques that can be utilized for the identification of students' perceptions toward generating ideas to produce innovative products. The sample of this study consists of 56 engineering students from the Department of Mechanical and Materials Engineering, Universiti Kebangsaan Malaysia (UKM), who have taken the Mechan...

A development of trajectory planning and simulation for a four degree-of-freedom (DOF) biped reciprocating gait orthosis (RGO) for paraplegic is presented in the paper. Trajectory planning in joint space is developed using linear segments with parabolic blends (LSPB) method and presented graphically. The design of the RGO structure is developed in...

This paper presents the reliability of the Taguchi Method for improving the product and process quality in the industrial environment. The purpose is to signify the applicability of the Taguchi method in process optimization. The application of the Taguchi design of experiment (DOE) is widely reported and published but the success of the Taguchi me...

E-waste recycling is a growing sector in the reverse supply chain and the main purpose of recycling is to recover precious materials making these recycling activities economically interesting. To increase vibrancy of this activity, third party logistic (3PLs) are used to carry out most of the logistic functions that contribute to the competitive ad...

Design for Upgradability (DfU) is one of remanufacturing strategies that extend the product lifetime through the functional enrichment of the product. Multiple Life Cycle products (MLPs) are designed with ease-of-upgrade features to allow for product upgrading to be made once the product is not functioning or becomes obsolete. To date, researches o...

In this paper, a method of extracting information in estimating orientation of vision system based on optical flow is presented. The method called angle discrete interval selection technique (ADIST) is proposed to estimate an angle by extracting optical flow information which consists of less noise interference. The performance of ADIST is compared...

In recent years, the productivity of machine tools has been significantly improved by using computer-based CAD/CAM systems for Computer Numerical Control (CNC). Various types of CAM software in the market that provide tool path programming and can be applied for different types of the machining process such as drilling, milling, and turning. Howeve...

Computer numerical control (CNC) machines have been widely used in automotive manufacturing industries especially of machining operation in automotive part such as engine body and cylinder. One of the key features that improve efficiency of CNC machining is through the optimization of tool path. Previous researcher to optimize tool path has premedi...

The interests of various economies in improving and expanding the growth of small and medium enterprises (SMEs) have thrived for a few years, particularly in the automotive sector. Although there are several supporting programs, SMEs face a large number of issues in their operation and performance. One of the successful techniques towards achieving...

Today, in most of metal machining process, Computer Numerical Control (CNC) machine tools have been very popular due to their efficiencies and repeatability to achieve high accuracy positioning. One of the factors that govern the productivity is the tool path travel during cutting a work piece. It has been proved that determination of optimal cutti...

The competitive environment of global markets has forced many manufacturers to select the most appropriate supply chain network (SCN) for reduction of total costs and wasted time. Cost reduction and selection of the appropriate length of each period are two important factors in the competitive market that are often not addressed comprehensively by...

Currently, most companies that act on both domestic and global markets experience a growing international competition and recognize the importance to reduce manufacturing lead time. One of the industries that has to face this globalization challenges is the machining industry. In general, machining can be done manually or automatically, better know...

Currently, most companies that conduct business in both domestic and global markets are facing growing international competition and recognize the importance of reducing manufacturing lead time, for example, companies in the machining industry. In general, machining can be performed manually, automatically or by Computer Numerical Control (CNC). Th...

In recent years, the productivity of machine tools have been significantly improved by using computer based CAD/CAM systems for Computer Numerical Control(CNC) program generation. There are many CAM software in the market that provide tool path programming and can be applied to different types of machining. However, in most cases the efficiency of...

The increasing number of parts variants on an assembly line requires an improvement for a cost efficient and flexible parts supply system. For that reason, the Set Parts Supply (SPS) system was introduced by Toyota as a new material handling system for supplying parts in sets based on the kitting concept. In this study, we investigate the considera...

This paper presents a technique on how to estimate heading direction of a moving vision system such as mobile robot. The heading direction is represented by estimation angle which is generated by optical flow vectors threshold technique (OFVTT). The utilizations of optical flow field generated based on Horn-Schunck and Lucas-Kanade methods are esse...

This paper presents development of control system for one side hip-knee joint of reciprocating gait orthosis (RGO) that aim to aid upright ambulation for paraplegic. The developed RGO structure is equipped with four direct current (DC) servo motors to deliver torque and provide ability for patient to walk. A control system with PID controller for D...

In this study, we proposed a mathematical model for four-level defective goods supply chain with imperfect quality of commodity components in an uncertain state to maximize profit of supply chain. It is assumed that the inspection of incoming parts in suppliers is randomly done and incomplete. This lead some of the manufactured products will not be...

One of the most important competitive criteria in the global marketplace is keeping the customer satisfaction. Timely delivery and cost of finished goods are two important factors for satisfaction of customers. In this study, we proposed a mathematical model to improve inventory control of defective goods supply chain by Available Time Limitation (...

A method of extracting information in estimating heading angle of vision system is presented. Integration of grey-level cooccurrence matrix (GLCM) in an area of interest selection is carried out to choose a suitable region that is feasible for optical flow generation. The selected area is employed for optical flow generation by using Horn-Schunck m...

In this paper, we present a new method for ranking generalized trapezoidal fuzzy numbers (GTrFNs) based on Ochiai index and Hurwicz criterion. The proposed ranking method considers all types of decision makers' perspective such as optimistic, neutral and pessimistic which is crucial in solving decision-making problems. The proposed method can discr...

In this paper, a technique of motion processing and analysis based on optical flow to gather information of heading direction from a vision system is presented. Instead of using the complete frame to determine the heading direction, in this paper, a region of interest (ROI) is used to calculate the heading direction. The selection of this ROI is ba...

Supply chain management (SCM) is a field of study which covers a wide range of research issues involving strategic to operational models. In the past two decades, SCM has drawn much attention from manufacturers and organizations for optimizing their operations. In this paper, a mathematical model to optimize costs of the supply chain for defective...