Sulaiman Fadlallah

Bacterial foraging-optimized PID control of a two-wheeled machine with a two-directional handling mechanism

Abstract This paper presents the performance of utilizing a bacterial foraging optimization algorithm on a PID control scheme for controlling a five DOF two-wheeled robotic machine with two-directional handling mechanism. The system under investigation provides solutions for industrial robotic applications that require a limited-space working environment. The system nonlinear mathematical model, derived using Lagrangian modeling approach, is simulated in MATLAB/Simulink® environment. Bacterial foraging-optimized PID control with decoupled nature is designed and implemented. Various working scenarios with multiple initial conditions are used to test the robustness and the system performance. Simulation results revealed the effectiveness of the bacterial foraging-optimized PID control method in improving the system performance compared to the PID control scheme.

Assessment of personal care and medical robots from older adults' perspective

Abstract Demographic reports indicate that population of older adults is growing significantly over the world and in particular in developed nations. Consequently, there are a noticeable number of demands for certain services such as health-care systems and assistive medical robots and devices. In today’s world, different types of robots play substantial roles specifically in medical sector to facilitate human life, especially older adults. Assistive medical robots and devices are created in various designs to fulfill specific needs of older adults. Though medical robots are utilized widely by senior citizens, it is dramatic to find out into what extent assistive robots satisfy their needs and expectations. This paper reviews various assessments of assistive medical robots from older adults’ perspectives with the purpose of identifying senior citizen’s needs, expectations, and preferences. On the other hand, these kinds of assessments inform robot designers, developers, and programmers to come up with robots fulfilling elderly’s needs while improving their life quality.

Design, Modelling, and Control of a Portable Leg Rehabilitation System

In this work, a novel design of a portable leg rehabilitation system (PLRS) is presented. The main purpose of this paper is to provide a portable system, which allows patients with lower limb disabilities to perform leg and foot rehabilitation exercises anywhere without any embarrassment compared to other devices that lack the portability feature. The model of the system is identified by inverse kinematics and dynamics analysis. In kinematics analysis, the pattern of motion of both leg and foot holders for different modes of operation has been investigated. The system is modeled by applying Lagrangian dynamics approach. The mathematical model derived considers calf and foot masses and moment of inertias as important parameters. Therefore, a gait analysis study is conducted to calculate the required parameters to simulate the model. PD controller and PID controller are applied to the model and compared. The PID controller optimized by Hybrid Spiral-Dynamics Bacteria-Chemotaxis (HSDBC) algorithm provides the best response with a reasonable settling time and minimum overshot. The robustness of the HSDBC-PID controller is tested by applying disturbance force with various amplitudes. A setup is built for the system experimental validation where the system mathematical model is compare with the estimated model using System Identification Toolbox. A significant difference is observed between both models when applying the obtained HSDBC-PID controller for the mathematical model. The results of this experiment are used to update the controller parameters of the HSDBC-optimized PID.

Modelling the trends of vehicle-emitted pollutants in Salalah, Sultanate of Oman, over a 10-year period

From 2004 to 2014, a significant increase in the number of vehicles in Salalah, Oman, has been observed and is related to the fact that the city has become a more popular tourist destination. Due to this rise in the number of vehicles, traffic jams have become a serious problem in Salalah. Therefore, this study aims to assess carbon monoxide (CO), nitrogen oxides (NOx), and carbon dioxide (CO2) from 2004 to 2014 for the Salalah region using the CALPUFF modelling system. Although the number of vehicles gradually increased in the area, the pollutant concentration levels fluctuated. CALPUFF results illustrated that CO levels were within the allowable concentrations assigned by the U.S. Environmental Protection Agency (EPA) standards, but NOx and CO2 concentrations were higher than the criterion limits set by the EPA and the Ontario Ministry of the Environment and Climate Change’s emission standards. Since Salalah is a coastal city, wind blowing toward the land from the sea significantly affects the dispersion of pollutants. Additionally, most of the maximum concentrations of the three pollutants were located near the centers of the streets. Replacing roundabouts with flyovers might significantly reduce traffic jams and vehicle-emitted pollutants in Salalah.

Hybrid spiral-dynamic bacteria-chemotaxis algorithm with application to control two-wheeled machines

Abstract This paper presents the implementation of the hybrid spiral-dynamic bacteria-chemotaxis (HSDBC) approach to control two different configurations of a two-wheeled vehicle. The HSDBC is a combination of bacterial chemotaxis used in bacterial forging algorithm (BFA) and the spiral-dynamic algorithm (SDA). BFA provides a good exploration strategy due to the chemotaxis approach. However, it endures an oscillation problem near the end of the search process when using a large step size. Conversely; for a small step size, it affords better exploitation and accuracy with slower convergence. SDA provides better stability when approaching an optimum point and has faster convergence speed. This may cause the search agents to get trapped into local optima which results in low accurate solution. HSDBC exploits the chemotactic strategy of BFA and fitness accuracy and convergence speed of SDA so as to overcome the problems associated with both the SDA and BFA algorithms alone. The HSDBC thus developed is evaluated in optimizing the performance and energy consumption of two highly nonlinear platforms, namely single and double inverted pendulum-like vehicles with an extended rod. Comparative results with BFA and SDA show that the proposed algorithm is able to result in better performance of the highly nonlinear systems.

Transient dynamic impact suppression of a Baja chassis using frontal and rear shock absorbers

ABSTRACT This paper investigates the behaviour of impact loading on a Baja vehicle chassis with frontal and rear shock absorbers, using transient dynamic analysis under different assumptions of contact conditions. Using a Baja car, a transient dynamic impact is performed in ANSYS Workbench 14.0, where the maximum deformation, stress and strains are calculated over duration of the particular impact. The mathematical model of the chassis is derived based on Kelvin model in order to design the best parameters of stiffness and damping coefficient in shock absorbers to minimise the deformation of the frame with the same impact. To study the effects of shock absorber under loading on a vehicle chassis, multiple finite element simulations are performed with different methodologies. Each methodology uses a different assumption on loading and boundary conditions, which leads to different results.