Mohammed A. H. Ali
Universiti Malaya, Faculty of Engineering, Faculty Member
- Dr. Mohammed Abdo Hashem is currently working as Senior Lecturer (Assistant Professor) with the department of Mechani... moreDr. Mohammed Abdo Hashem is currently working as Senior Lecturer (Assistant Professor) with the department of Mechanical Engineering at Faculty of Engineering in University of Malaya starting from April 2021-Onwards. He was working previously in Universiti Malaysia Pahang (UMP) for the period 2015-2021, where he was appointed as a senior lecturer and leader of control, software and automation teaching and research group at the Faculty of Manufacturing Engineering. He was publishing more than 60 papers in top ISI Journals with 6 patents and 12 Research grants as leader.edit
Myocarditis has been discovered to be a significant complication of coronavirus disease 2019 (COVID-19), a condition caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. COVID-19 myocarditis seems to have... more
Myocarditis has been discovered to be a significant complication of coronavirus disease 2019 (COVID-19), a condition caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. COVID-19 myocarditis seems to have distinct inflammatory characteristics, which make it unique to other viral etiologies. The incidence of COVID-19 myocarditis is still not clear as a wide range of figures have been quoted in the literature; however, it seems that the risk of developing myocarditis increases with more severe infection. Furthermore, the administration of the mRNA COVID-19 vaccine has been associated with the development of myocarditis, particularly after the second dose. COVID-19 myocarditis has a wide variety of presentations, ranging from dyspnea and chest pain to acute heart failure and possibly death. It is important to catch any cases of myocarditis, particularly those presenting with fulminant myocarditis which can be characterized by signs of heart failure and arry...
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Owing to the increasing demand for rehabilitation services, robotics have been engaged in addressing the drawbacks of conventional rehabilitation therapy. This paper focuses on the modelling and control of a three-link lower limb... more
Owing to the increasing demand for rehabilitation services, robotics have been engaged in addressing the drawbacks of conventional rehabilitation therapy. This paper focuses on the modelling and control of a three-link lower limb exoskeleton for gait rehabilitation that is restricted to the sagittal plane. The exoskeleton that is modelled together with a human lower limb model is subjected to a number of excitations at its joints while performing a joint space trajectory tracking, to investigate the effectiveness of the proposed controller in compensating disturbances. A particle swarm optimised active force control strategy is proposed to facilitate disturbance rejection of a conventional proportional-derivative (PD) control algorithm. The simulation study provides considerable insight into the robustness of the proposed method in attenuating the disturbance effect as compared to the conventional PD counterpart without compromising its tracking performance. The findings from the st...
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This paper aims to develop a new mobile robot path planning algorithm, called generalized laser simulator (GLS), for navigating autonomously mobile robots in the presence of static and dynamic obstacles. This algorithm enables a mobile... more
This paper aims to develop a new mobile robot path planning algorithm, called generalized laser simulator (GLS), for navigating autonomously mobile robots in the presence of static and dynamic obstacles. This algorithm enables a mobile robot to identify a feasible path while finding the target and avoiding obstacles while moving in complex regions. An optimal path between the start and target point is found by forming a wave of points in all directions towards the target position considering target minimum and border maximum distance principles. The algorithm will select the minimum path from the candidate points to target while avoiding obstacles. The obstacle borders are regarded as the environment’s borders for static obstacle avoidance. However, once dynamic obstacles appear in front of the GLS waves, the system detects them as new dynamic obstacle borders. Several experiments were carried out to validate the effectiveness and practicality of the GLS algorithm, including path-pl...
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This paper presents a literature review on the common control systems that have been used for robotic manipulators with a very higher concern on PID and active force control (AFC).The control of manipulator is divided into two main... more
This paper presents a literature review on the common control systems that have been used for robotic manipulators with a very higher concern on PID and active force control (AFC).The control of manipulator is divided into two main systems, namely are linear and non-linear control systems. A nonlinear system is used to overcome un-modeled dynamics, variable payload, fiction and disturbance torque, variation, and noise. PID controller has enhanced the performance of the manipulator in certain cases such as reducing system vibration and maintaining the tracking errors of the manipulator. On the other hand, AFC is a robust and much viable controller in comparison with others ordinary strategies in controlling dynamical systems such as robotic manipulator
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This paper presents a design and modeling of wheeled mobile robot (MWR) when navigating autonomously in environment such as road and factory. It needs a good and robust design and control for wheeled mobile robot to move from one to... more
This paper presents a design and modeling of wheeled mobile robot (MWR) when navigating autonomously in environment such as road and factory. It needs a good and robust design and control for wheeled mobile robot to move from one to another points with smooth moving and small tracking errors. This paper is focused on mechanical design and modeling of wheeled mobile robot. Autodesk inventor software is used to draw the design of the WMR because this software is simple to make any design and a wheeled mobile robot structure is designed with a center of gravity to be located below the axle wheels level. The wheeled mobile robot is driven using two differential drive and two castor wheels to balance robot while it is moving in the environment. Two kinds of coordinate systems are used to describe the movement of the robot in the environment; namely are Local and global coordinate system; where local is related to the heading angle and the deferential wheel shaft, however the global descr...
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SUMMARY The design and experimental works of an autonomous robotic platform for road marks painting are presented in this paper as the first autonomous system of its kind. The whole system involves two main sub-systems, namely: an... more
SUMMARY The design and experimental works of an autonomous robotic platform for road marks painting are presented in this paper as the first autonomous system of its kind. The whole system involves two main sub-systems, namely: an autonomous mobile robot navigation system which is used for recognizing the roads and estimating the position of road marks, and automatic road marks painting system that is attached to the mobile robot platform to control the spray of the paint on the road’s surface. The experimental results show the capability of the proposed system to perform the task of autonomous road marks painting with accuracy of ±10 cm.
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The performance and reliability of an internal combustion engine depend on the robustness of the engine crankshaft as it is one of its important moving component. An internal combustion engine is affected by the vibration activities of a... more
The performance and reliability of an internal combustion engine depend on the robustness of the engine crankshaft as it is one of its important moving component. An internal combustion engine is affected by the vibration activities of a crankshaft. This vibration performance is hard to determine due to the complex nature of the crankshaft. To avoid failure of an engine crankshaft, calculation of the crankshaft strength becomes an importance component. In this paper, fatigue, failure and harmonic response analysis of an internal combustion engine by Finite Element method (FEM) using ANSYS workbench were carried out. The analysis is carried out in ANSYS static structural, mechanical solver on a structural steel material. Result from the transient analysis indicates presence of stress at the crankpin journals and with the appearance of deformation at its crank nose. The failure analysis safety factor is high in the Gerber theory being a structural steel material.
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Abstract One of the important component of working machines or conveyer belt is the roller bearing. They are applied in different sectors ranging from automotive to heavy duty machineries in high speed drills. Their performance greatly... more
Abstract One of the important component of working machines or conveyer belt is the roller bearing. They are applied in different sectors ranging from automotive to heavy duty machineries in high speed drills. Their performance greatly affects the machines. This study illustrate the analysis of the contact stress developed in a roller bearing using ANSYS software. The Finite Element simulating results revels maximum stress distribution value of 6.597E-09 MPa under the applied loading condition appearing on the roller balls. The total moment for the variation to time is 2.5868E-07 experienced at 7.7 s while the relative rotation in the Z-direction is at its peak at 6 s. Therefore, this study shows that FEA in ANSYS has provide a faster and cheaper method compared to the production of numerous prototypes.
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Automotive engineering design has recently focused majorly on the stress analysis and optimization of a connecting rod with keen emphases to the vital parameters such as deformation, stress, fatigue and strain, factor safety, life values... more
Automotive engineering design has recently focused majorly on the stress analysis and optimization of a connecting rod with keen emphases to the vital parameters such as deformation, stress, fatigue and strain, factor safety, life values among others. The performance of a connecting rod in an automobile engine is influenced by its design and weight. Hence, for the production of a durable, cheaper and lightweight connecting rod, analysis and optimization become necessary. This article provides a review of some vital work done by various researchers in designing, analyzing and optimization of connecting rod of an engine using Finite element analysis in ANSYS workbench A comprehensive comparison table and graphs for the reviewed research articles have been provided. The article will serve as a stepping stone for both old and new researchers in the field of automotive design.
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Connecting rods are mechanical components used for generating motion from a crankshaft’s piston alternating motion. There have been numerous reported cases of connecting rod failure based on the structural design, loading type and the... more
Connecting rods are mechanical components used for generating motion from a crankshaft’s piston alternating motion. There have been numerous reported cases of connecting rod failure based on the structural design, loading type and the type of materials used. The main aim of this paper is to explore strength analysis investigation of a connecting rod using different materials (structural steel, aluminum alloy, titanium, and Magnesium alloy). The results obtained were compared and analyzed in terms of strength, deformation, Von-misses stress, strain and the safety factor to identify the best material capable of withstanding the subjected force. The model was first design with SolidWorks software and subsequently imported into the ANSYS workbench. Result from the analysis shows that structural steel has the highest strength compared to the other materials.
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Eye tracking is a useful technique for detecting autism spectrum disorder (ASD). One of the most important aspects of good learning is the ability to have atypical visual attention. The eye-tracking technique provides useful information... more
Eye tracking is a useful technique for detecting autism spectrum disorder (ASD). One of the most important aspects of good learning is the ability to have atypical visual attention. The eye-tracking technique provides useful information about children’s visual behaviour for early and accurate diagnosis. It works by scanning the paths of the eyes to extract a sequence of eye projection points on the image to analyse the behaviour of children with autism. In this study, three artificial-intelligence techniques were developed, namely, machine learning, deep learning, and a hybrid technique between them, for early diagnosis of autism. The first technique, neural networks [feedforward neural networks (FFNNs) and artificial neural networks (ANNs)], is based on feature classification extracted by a hybrid method between local binary pattern (LBP) and grey level co-occurrence matrix (GLCM) algorithms. This technique achieved a high accuracy of 99.8% for FFNNs and ANNs. The second technique ...
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A robust control algorithm for tracking the mobile robot in a pre-planned path during passing through complicated environments such as in roundabout is presented in this paper. The proposed algorithm is derived from the kinematic and... more
A robust control algorithm for tracking the mobile robot in a pre-planned path during passing through complicated environments such as in roundabout is presented in this paper. The proposed algorithm is derived from the kinematic and dynamic of 3wheeled Non-holonomic mobile robot motion. The control scheme is performed using Resolved Acceleration Control, Active Force Control strategy or mixed of them in Simulink-MATLAB, which are compared with each other in the matter ofenabling the robot to follow the predefined path while applying disturbances. Results show the capability of this controller to track the robot on the pre-defined path and remove the effect of the disturbances.
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The purpose of this paper is to review real-time control motion algorithms for wheeled mobile robot (WMR) when navigating in environment such as road. Its need a good controller to avoid collision with any disturbance and maintain a track... more
The purpose of this paper is to review real-time control motion algorithms for wheeled mobile robot (WMR) when navigating in environment such as road. Its need a good controller to avoid collision with any disturbance and maintain a track error with zero level. The controllers is used with and other aiding sensors to measure the WMR’s velocities, posture, and interference to estimate the needed torque of mobile robot due to wheel rotating. Four main categories for wheeled mobile robot control that have been found in literature which are namely: Kinematic based controller, Dynamic based controllers, artificial intelligence based control system, and Active Force control. A MATLAB/Simulink software is the main software to simulate and implement control system. The real-time toolbox in MATLAB/SIMULINK are used to receive/send data from sensors/to actuator with existing of real path disturbances
This paper present a design and modeling for a two link robotic manipulator for grading and sorting system. The mechanical design calculation of the robotic manipulator is accomplished firstly to estimate the torques and positions of... more
This paper present a design and modeling for a two link robotic manipulator for grading and sorting system. The mechanical design calculation of the robotic manipulator is accomplished firstly to estimate the torques and positions of manipulator that are required to move a certain payloads from one to another position, which is resulted by choosing of the right electrical motors. The mechanical design drawings for this manipulator system are fully done using Autodesk Inventor Software which concerns the real joint of the robotic manipulator. The dynamic equation of the robotic manipulator system is derived using the Lagrange equation which is then represented in the state space method to make simple for utilization in Simulation and real-time systems.
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In this paper, a Laser simulator search graph approach for free-path search graph in complex unstructured environments has been developed and implemented for a robust mobile robot navigation system through the roundabout environments... more
In this paper, a Laser simulator search graph approach for free-path search graph in complex unstructured environments has been developed and implemented for a robust mobile robot navigation system through the roundabout environments settings. The principle and methodology of laser simulator approach was clearly presented and explained for visibility searching of the optimum path in unknown environments with existence of some motion constraints and rules. The proposed approach gives the possibility for mobile robot to effectively track the path when countering a roundabout with and without obstacle and considering a number of scenarios. The algorithm is applied into tow kinds of setup: first it is simulated using MATLAB with the grid map used to create the road roundabout environment and select the path according to the respective road rules. Secondly it is used to recognize the roundabout in the real roundabout from sequence of images and enable the mobile robot for making decision...
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A real-time roundabout detection and navigation system for smart vehicles and cities using laser simulator–fuzzy logic algorithms and sensor fusion in a road environment is presented in this paper. A wheeled mobile robot (WMR) is supposed... more
A real-time roundabout detection and navigation system for smart vehicles and cities using laser simulator–fuzzy logic algorithms and sensor fusion in a road environment is presented in this paper. A wheeled mobile robot (WMR) is supposed to navigate autonomously on the road in real-time and reach a predefined goal while discovering and detecting the road roundabout. A complete modeling and path planning of the road’s roundabout intersection was derived to enable the WMR to navigate autonomously in indoor and outdoor terrains. A new algorithm, called Laser Simulator, has been introduced to detect various entities in a road roundabout setting, which is later integrated with fuzzy logic algorithm for making the right decision about the existence of the roundabout. The sensor fusion process involving the use of a Wi-Fi camera, laser range finder, and odometry was implemented to generate the robot’s path planning and localization within the road environment. The local maps were built us...
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A robust control algorithm for tracking a wheeled mobile robot navigating in a pre-planned path while passing through the road’s roundabout environment is presented in this article. The proposed control algorithm is derived from both the... more
A robust control algorithm for tracking a wheeled mobile robot navigating in a pre-planned path while passing through the road’s roundabout environment is presented in this article. The proposed control algorithm is derived from both the kinematic and dynamic modelling of a non-holonomic wheeled mobile robot that is driven by a differential drive system. The road’s roundabout is represented in a grid map and the path of the mobile robot is determined using a novel approach, the so-called laser simulator technique within the roundabout environment according to the respective road rules. The main control scheme is experimented in both simulation and experimental study using the resolved-acceleration control and active force control strategy to enable the robot to strictly follow the predefined path in the presence of disturbances. A fusion of the resolved-acceleration control–active force control controller with Kalman Filter has been used empirically in real time to control the wheel...
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Given the current COVID-19 pandemic, medical research today focuses on epidemic diseases. Innovative technology is incorporated in most medical applications, emphasizing the automatic recognition of physical and emotional states. Most... more
Given the current COVID-19 pandemic, medical research today focuses on epidemic diseases. Innovative technology is incorporated in most medical applications, emphasizing the automatic recognition of physical and emotional states. Most research is concerned with the automatic identification of symptoms displayed by patients through analyzing their body language. The development of technologies for recognizing and interpreting arm and leg gestures, facial features, and body postures is still in its early stage. More extensive research is needed using artificial intelligence (AI) techniques in disease detection. This paper presents a comprehensive survey of the research performed on body language processing. Upon defining and explaining the different types of body language, we justify the use of automatic recognition and its application in healthcare. We briefly describe the automatic recognition framework using AI to recognize various body language elements and discuss automatic gestu...
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Robots are currently replacing humans in different tasks in various sectors. Among the vital features desirable in autonomous robots is the capability of navigating safely through a given environment. Robot navigation is a process... more
Robots are currently replacing humans in different tasks in various sectors. Among the vital features desirable in autonomous robots is the capability of navigating safely through a given environment. Robot navigation is a process designed with the ability of avoiding any hitches or obstacles while aiming at a specific predefined position. Many studies have been proposed to find solutions to robot path-planning problems. This paper presents a survey of the heuristic and classical path-planning approaches. Focal strengths, together with the weaknesses of these approaches, were also identified to provide deep insight for future studies. As several literature studies have recommended, classical methods might not be effective in real-time applications as a result of their failure to confront the unpredictable nature of the real-world. They require a considerable amount of computation and space, while heuristic-based methods can overcome real-world problems with some modifications. To su...
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Robots are currently replacing humans in different tasks in various sectors. Among the vital features desirable in autonomous robots is the capability of navigating safely through a given environment. Robot navigation is a process... more
Robots are currently replacing humans in different tasks in various sectors. Among the vital features desirable in autonomous robots is the capability of navigating safely through a given environment. Robot navigation is a process designed with the ability of avoiding any hitches or obstacles while aiming at a specific predefined position. Many studies have been proposed to find solutions to robot path-planning problems. This paper presents a bibliometric analysis of the relevant publications published from 2000 to 2020. The results show that 5385 articles were published in 1128 journals, hence indicating publication diversity. There is a steady rise in the yearly publication output, reflecting an increase in global research interest in the topic. In general, this research provides useful insight into path-planning research so that researchers in this area can better recognize the relevant research study topics and search for the appropriate research partners.
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A novel technique called laser simulator approach for visibility search graph-based path planning has been developed in this article to determine the optimum collision-free path in unknown environment. With such approach, it is possible... more
A novel technique called laser simulator approach for visibility search graph-based path planning has been developed in this article to determine the optimum collision-free path in unknown environment. With such approach, it is possible to apply constraints on the mobile robot trajectory while navigating in complex terrains such as in factories and road environments, as the first work of its kind. The main advantage of this approach is the ability to be used for both global/local path planning in the presence of constraints and obstacles in unknown environments. The principle of the laser simulator approach with all possibilities and cases that could emerge during path planning is explained to determine the path from initial to destination positions in a two-dimensional map. In addition, a comparative study on the laser simulator approach, A* algorithm, Voronoi diagram with fast marching and PointBug algorithms was performed to show the benefits and drawbacks of the proposed approac...