14 research outputs found

    Control of a Two-wheeled Machine with Two-directions Handling Mechanism Using PID and PD-FLC Algorithms

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    This paper presents a novel five degrees of freedom (DOF) two-wheeled robotic machine (TWRM) that delivers solutions for both industrial and service robotic applications by enlarging the vehicle′s workspace and increasing its flexibility. Designing a two-wheeled robot with five degrees of freedom creates a high challenge for the control, therefore the modelling and design of such robot should be precise with a uniform distribution of mass over the robot and the actuators. By employing the Lagrangian modelling approach, the TWRM′s mathematical model is derived and simulated in Matlab/Simulink®. For stabilizing the system′s highly nonlinear model, two control approaches were developed and implemented: proportional-integral-derivative (PID) and fuzzy logic control (FLC) strategies. Considering multiple scenarios with different initial conditions, the proposed control strategies′ performance has been assessed

    Students' Reluctance to Attend Office Hours: Reasons and Suggested Solutions

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    This paper focuses on investigating students’ reasons for their reluctance to attend faculty members’ office hours. Study participants included 500 male and female students from the Colleges of Engineering (n = 248) and Arts and Social Sciences (CASS) (n = 252) at Sultan Qaboos University (SQU). The study followed a descriptive-analytical approach, and a questionnaire was utilized to collect people’s views. The results of the study indicate that the rates of SQU students’ attendance to office hours were low, and some students (11.2%) do not attend at all as they consider these office hours a waste of time. The main reasons behind the students’ lack of interest in office hours were busy student timetables, conflicts between faculty office hours and students’ timetables, and easier and faster ways of getting information than visiting faculty members. Additional reasons were related to faculty members’ personalities and their discouraging attitudes toward attending office hours. The researchers recommend that SQU adopt a new strategy for encouraging faculty members to hold office hours, familiarizing students with the importance of office hours and assigning part of a course’s grades to meeting with faculty members’ office hours

    Temperature and air pollution relationship during heatwaves in Birmingham, UK

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    While temperature has long been known as a catalyst for pollutants to be more airborne, it is unclear how an increase in temperature affects air pollution during heatwaves. Through a regression analysis of the relationship between ozone (O3), particulate matter (PM10, particles less than 10 μm in diameter), nitrogen dioxide (NO2), and temperatures in urban and rural areas of Birmingham, it was found that during heatwaves, all pollutant levels rose at each site, with the maximum temperature coinciding with the peak levels of O3 and PM10. These findings established that the influence of temperature on air pollution did not change according to rural or urban locations although air pollutants (O3, PM10, and NO2) increased with increasing temperatures, particularly during heatwaves. Levels of ozone were found to increase by more than 50% with increases in temperature. This supports studies where the incidence of high levels of pollutants has conclusively been found to be much more prevalent during prolonged heatwaves. The implications of these findings are important to the establishment of long-term prevention measures in heatwave plans. When a heatwave is forecast, additional measures to reduce air pollutant concentrations may be appropriate when commencing emergency responses

    Design, Modelling and Control of a Portable Leg Rehabilitation System

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    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

    System Identification and HSDBC-Optimized PID Control of a Portable Lower-Limb Rehabilitation Device

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    The present paper introduces a novel portable leg rehabilitation system (PLRS) that is developed to provide the user with the necessary rehabilitation exercises for both the knee and ankle in addition to the portability feature to overcome the hardships associated with both effort and cost of hospitals and rehabilitation clinics’ steady sessions. Prior realizing the actual prototype, the proposed configuration was visualized using SolidWorks including its main components. Aiming to control the developed system, and given the fact that tuning controller parameters is not an easy task, Hybrid Spiral-Dynamics Bacteria-Chemotaxis (HSDBC) algorithm has been applied on the proposed control strategy in order to obtain a satisfactory performance. The obtained system performance was satisfactory in terms of desired elevation and settling time

    Sustainable humidity control in the built environment:Recent research and technological advancements in thermal driven dehumidification systems

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    As we navigate an era marked by significant environmental concerns and technological advancements, the search for energy-efficient and ecological friendly solutions is more critical than ever. One area of growing significance is the control of indoor humidity levels, which not only impacts human comfort and health but also the structural integrity and air quality within buildings. The challenge is to control these levels while lessening energy consumption and environmental impact. A feasible solution lies in the use of thermal-driven dehumidifiers, a promising technology that offers a sustainable approach to humidity control. Thermal-driven dehumidifiers have emerged as promising solutions for humidity control in various applications, owing to their energy-saving and eco-friendly features. Thus, the focus of this review paper is to explore the most recent advancements and enhancements in thermal-driven dehumidification technologies. This includes systems based on solid desiccant, liquid desiccant, and thermoelectricity. The study aims to fill the existing literature gaps, providing a thorough analysis of the current state of these technologies, their performance indicators, and their potential for future development. The study also explores the suitability of these technologies for different ambient conditions and humidity loads. It addresses critical characteristics such as dehumidification efficiency, cooling capacity, regeneration heat, and energy consumption. Each technology is thoroughly examined, including its suitability for various ambient conditions and humidity load scenarios. Specific real-world examples are examined to highlight these technologies' practical importance and possible influence in tackling humidity management concerns
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