Mustufa H. Abidi

Development of a virtual manufacturing assembly simulation system

Assembly operations are a key component of modern manufacturing systems. Designing, planning, and conducting assembly operations represent an important part of the cost of a product. Virtual reality provides an efficient and cost-effective solution to manufacturing design, planning, and prototyping. Still there are certain issues (such as data translation, integration of various hardware and software systems, and real-time collision detection) faced while applying this advanced technology to the assembly domain. For example, existing works focus on using virtual reality systems and environments mainly to design new products and to plan for assembly. Little focus has been given to develop virtual reality environments that contribute to train operators on assembly operations and to bridge the gap between design and implementation/execution of assembly. Therefore, the research work presented in this article focuses on developing a fully functional virtual manufacturing assembly simulation system that solves the issues related to virtual reality environments. The proposed system uses a virtual environment to create an interactive workbench that can be used for evaluating assembly decisions and training assembly operations. It is a comprehensive system that provides visual, auditory, tactile, as well as force feedback. The system works successfully even with large components.

Assistive technologies for hearing, and speaking impaired people: a survey

Abstract This study presents a novel method for evaluating the scientific research papers in the field of assistive technologies pertaining to different impairment conditions. The objectives are to understand the technologies used for addressing the needs of PWD by identifying relevant criteria for the assessment, explore the implications of these technologies in their lives and identify the gaps among certain technologies in assisting PWD. In this article, we reviewed around 40 research scientific papers in relation to the technologies used to assist PWD in their daily activities. A novel quantitative assessment methodology based on Multi-weighted Scoring Model (MWSM) has been developed. It is based on the judgement of clinical experts according to thirteen well-defined criteria. The proposed method is useful because it assesses the scientific studies related to PWD qualitatively according to efficient research coverage, as well as quantitatively in order to have good comparative judgment. Moreover, this method recognizes the research gap or areas which need further investigation and identifies the research papers that have good coverage of the respective criteria. Implications for Rehabilitation Human computer interface (HCI) solutions are critical for addressing the main issues facing people with disabilities (PWD) in their life. Assessment of scientific research papers according to well-defined criteria that address PWD needs would assist in verifying their suitability for PWDs. Novel quantitative assessment methodology is used for assessing these research papers using judgment of experienced researchers according to 13 well-defined criteria that have been weighted according to relevancy to different impairment groups. Identifying research papers that have good coverage of defined criteria and knowing the research area that needs further investigation by researchers and developers, would ultimately address the rehabilitation needs for PWD.

Layout design optimization of dynamic environment flexible manufacturing systems

The proper positioning of machine tools in flexible manufacturing system is one of the factors that lead to increase in production efficiency. Choosing the optimum position of machine tools curtails the total part handling cost between machine tools within the flexible manufacturing system. In this article, a two-stage approach is presented to investigate the best locations of the machine tools in flexible manufacturing system. The location of each machine tool is selected from the available specific and fixed locations in such a way that it will result in best throughput of the flexible manufacturing system. In the first stage of the two-stage approach, the throughput of randomly selected locations of the machine tool in flexible manufacturing system is computed by proposing a production simulation system. The production simulation system utilizes genetic algorithms to find the locations of the machine tools in flexible manufacturing system that achieve the maximum throughput of the flexible manufacturing system. In the second stage, the generated locations are fed into artificial neural network to find a relation between a machine tool’s location and the throughput that can be used to predict the throughput for any other set of locations. Artificial neural network will result in mitigating the computational time.

Development and Evaluation of a Virtual Assembly Trainer

This paper discusses the development and evaluation of a virtual assembly training system for the first Saudi Arabian car prototype (Gazal-1) fender assembly. An evaluation study was conducted to compare 3 training scenarios: Traditional Engineering (TE), Computer Aided Design Environment (CADE), and immersive virtual reality (IVR). 15 students from King Saud University were randomly assigned to the different training conditions. After that, transfer of training to the actual assembly was evaluated. Performance measures used to assess transfer of training include time to complete task and number of frustration points during task. The results of the evaluation study suggest that the participants of IVR training condition performed better than the other two conditions. Therefore, virtual assembly simulation using virtual reality systems might be useful for training operators who will be conducting assembly operations.

Analysis of defects in clean fabrication process of friction stir welding

Abstract Striving for cleaner production is a sought-after manufacturing philosophy. Friction stir welding (FSW) is a joining technique with par excellence and far less invasive to the environment than even best conventional welding processes. It is energy efficient and free from consumables, affluent and radiations. It is, thus, accepted as a clean welding process that can produce acceptable quality joints. It suffers from some major challenges of defects of its own kind that subject the process open to improvements so as to prove itself a reliable production process. This study presents a holistic characterization of defects commonly found in FSW joints. The finding of the present study reveals that most defects are caused by inadequate heat generation, improper material movement around the pin and inadequate material consolidation behind the pin. The amount of heat generation and material stirring depends on several FSW parameters which may lead to the defect formation, if not selected properly. The results reported in this work are derived from sound literature support and experimentation. Prescriptions are made in the form of characteristics of defects such as likelihood of their location, main responsible parameters along with the recommendations for minimizing them.

On multistage approach for flexible routing in flexible manufacturing systems

Optimizing flexible routing in flexible manufacturing systems is one of the aspects that increase the efficiency of flexible manufacturing systems especially in dynamic environment systems. This article presents a multistage approach to solve flexible routing problem in flexible manufacturing systems. Multistage approach includes three stages; the first stage is a production simulation system to find the fitness of the flexible manufacturing systems corresponding to different products’ routes’ groups. The second stage proposes an artificial neural network approach to predict the products’ routes’ group in flexible manufacturing systems. The last stage combines genetic algorithms and artificial neural network to optimize proper routes for all product types in flexible manufacturing systems. Multistage approach proposed in this study aims to reduce the computational time required to obtain and optimize the flexible routes in flexible manufacturing systems. The results of this study show that the artificial neural network can be used efficiently to predict the flexible routes in flexible manufacturing systems and it reduces the computational time for routes’ optimization required with production simulation system. This characteristic improves the flexibility of flexible manufacturing systems since it can be adapted frequently against any change in production ratios.

Assessment and comparison of immersive virtual assembly training system

This paper presents the assessment and comparison of a virtual assembly training system for the first Saudi Arabian car prototype fender assembly. An assessment study was conducted to compare three training scenarios: Traditional Engineering, Computer Aided Design Environment, and Immersive Virtual Reality (IVR). Fifteen students from King Saud University were randomly assigned to the different training conditions. After that transfer of training to the actual assembly was evaluated. Performance measures used to assess transfer of training include time to complete task and number of frustration points during task. Furthermore, experiments were conducted to evaluate the effect of number of trainings in IVR environment on user’s performance while performing the virtual assembly. The results of study suggest that the participants of IVR training condition performed better than the other two conditions. Also, it was seen that the participants with more number of training within IVR performed better while doing virtual assembly.

Investigation of Micro-EDM input Parameters on Various Outputs in Machining Ni-Ti Shape Memory Alloy Using Full Factorial Design

Micro Electric Discharge Machining (μ-EDM) is a non-traditional machining process which is used for drilling micro holes in a high strength-to-weight ratio advanced engineering materials like shape memory alloys that have many applications in the field of aerospace and medical sciences. However, in order to achieve the desired output responses the process control parameters of the machine have to be set at an optimal setting. In this research work, an investigation has been made to study the influence of the input parameters (such as capacitance, discharge voltage and electrode material) on the micro-EDM process output responses (such as MRR, TWR, Ra and circularity of the micro-holes) while drilling the micro-holes on Ni-Ti shape memory alloy. The full factorial design based study resulted in a set of recommended values for input variables to obtain the desired output. Mathematical predictive models have also been developed, which predict good values for the output responses.

Development and Evaluation of the Virtual Prototype of the First Saudi Arabian-Designed Car

Prototyping and evaluation are imperative phases of the present product design and development process. Although digital modeling and analysis methods are widely employed at various product development stages, still, building a physical prototype makes the present typical process expensive and time consuming. Therefore, it is necessary to implement new technologies, such as virtual prototyping, which can enable industry to have a rapid and more controlled decision making process. Virtual prototyping has come a long way in recent years, where current environments enable stereoscopic visuals, surround sound and ample interaction with the generated models. It is also important to evaluate how representative the developed virtual prototype is when compared to the real-world counterpart and the sense of presence reported by users of the virtual prototype. This paper describes the systematic procedure to develop a virtual prototype of Gazal-1 (i.e., the first car prototype designed by Saudi engineers) in a semi-immersive virtual environment. The steps to develop a virtual prototype from CAD (computer-aided design) models are explained in detail. Various issues involved in the different phases for the development of the virtual prototype are also discussed comprehensively. The paper further describes the results of the subjective assessment of a developed virtual prototype of a Saudi Arabian-designed automobile. User’s feedback is recorded using a presence questionnaire. Based on the user-based study, it is revealed that the virtual prototype is representative of the real Saudi Arabian car and offers a flexible environment to analyze design features when compared against its physical prototype. The capabilities of the virtual environment are validated with the application of the car prototype. Finally, vital requirements and directions for future research are also presented.

Utilizing sensors networks to develop a smart and context-aware solution for people with disabilities at the workplace (design and implementation)

The developments and improvements in human–computer interaction and information and communication technologies have resulted in innovative assistive technology (AT) solutions for the people with disabilities (PWDs). Although, there have been many new ideas and technologies for assisting the PWDs, still very few of them have considered the workplace environment. Therefore, there is a need to develop a comprehensive universal AT solution that can maximize the PWDs productivity at work. In this work, an AT and smart context-aware solution has been developed to assist the PWDs at the workplace. This has been achieved through the designing and the implementation of a smart unified interface to guide and assist the PWDs. A wireless sensor network has been employed in this context-aware smart solution in order to track and determine user’s location. The unified interface is adaptive and includes four modules that are smart helping, smart communication, smart editor, and auto emergency response. A proper AT process and technological design considerations have been adopted to achieve a comprehensive, universal, adaptive, and context-aware solution.