A set of guidelines, illustrated with a case study of an international FMEA project facilitated with a Google Groups website, is aimed to help organizations optimize their use of Web-based collaborative environments. ...
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A set of guidelines, illustrated with a case study of an international FMEA project facilitated with a Google Groups website, is aimed to help organizations optimize their use of Web-based collaborative environments. An FMEA team assembled in a physical location has drawbacks that can hamper performance and feasibility and the processes. Provision of an online venue for FMEAs enables collaboration with external entities, thus improving the quality of the information developed. The purpose of the FMEA process is to bring together people with unique experiences and perspectives to generate information that no one person could visualize alone. A process FMEA must have manufacturing engineers or people involved directly with the process, whereas a design FMEA may have a manufacturing representative to provide additional perspective. A meeting conducted by the FMEA team included elements such as limited period time for completing team tasks and confirming website availability.
Studying adsorption in polymers is important for many applications. We present results on real-time in situ adsorption of ethanol and water in thin polymethyl methacrylate (PMMA) layers using attenuated total reflecti...
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The implementation of a bioinspired PID-based controller with online tuning capabilities is developed for obstacle following/avoidance of a nonholonomic mobile robot. An innovative mixture of the conventional PID cont...
The implementation of a bioinspired PID-based controller with online tuning capabilities is developed for obstacle following/avoidance of a nonholonomic mobile robot. An innovative mixture of the conventional PID controller and particle swarm optimization (PSO), which has a strong capability of adaptation across unknown scenarios, reduced objective error, brings us a novel online tuning methodology that can derive optimal controller parameters for a given scenario. It is appropriate for a kind of plant without prior knowledge or established mobile robot model. Computer simulation for obstacle following/avoidance is carried out in four different scenarios using the CoppeliaSim software and the EVA mobile robot platform. The effectiveness of the proposed control algorithm is demonstrated trough the simulation experiment, which shows its superior performance in the training scenario, including an overshoot of 20.1 %, a settling time of 10 seconds, and a steady-state error of 0.76%.
In order to design a wave energy generating system of a floating type, a 6- Degrees Of Freedom (DOF) motion technique was applied to Computational Fluid Dynamics (CFD) analysis on this floating body and the behavior i...
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Floating ROVs have extensive applications on oceanographic research, environmental monitoring, and search and rescue operations. In this work, two levels of floating ROV stabilization is realized. First, the intrinsic...
Floating ROVs have extensive applications on oceanographic research, environmental monitoring, and search and rescue operations. In this work, two levels of floating ROV stabilization is realized. First, the intrinsic stability is induced by the design of center of mass and moment of inertia based on the stability analysis, such that the ROV can always keep its upwards standing configuration. Besides, an underactuated control method for this novel untethered tumbler floating (TF) ROV is introduced for stabilization, which effectively enhances the stabilization efficiency based on the attitude controller. The model considering rigid body dynamics based on Euler equations, and nonlinear controllability with one, two, or three torques are analyzed serving for the moment of inertia design and underactuated controller. Simulation experiments are conducted to validate the efficacy of our approach, and the results demonstrate its effectiveness for stabilizing the TF-ROV.
Another factor that has a very significant effect on sheet formability is the loading path. Indeed, non-linear strain paths cause the forming limit curve (FLC) to translate in principal strain space and therefore the ...
Another factor that has a very significant effect on sheet formability is the loading path. Indeed, non-linear strain paths cause the forming limit curve (FLC) to translate in principal strain space and therefore the actual FLC for a given location on a part may be quite different from the as-received FLC. Consequently, the virtual design of a forming process will only be reliable if the forming limits used to assess the forming severity of the part were determined with due consideration of the (non-linear) strain paths in each critical location of the part. The FLC of sheet metals have often been predicted using the MK method which was proposed by Marciniak and Kuczynski (1967) and which models the inhomogeneity of the sheet material by a very shallow groove. Predictions of theoretical FLC using the MK method generally assume plane stress conditions, but in this work the MK analysis was modified to consider both the nonlinearity of the loading path and the presence of a through-thickness stress, simultaneously. Different magnitudes of prestrain were applied to a virtual sheet so as to simulate bi-linear strain paths and different values of the normal stress were applied for the prediction of the FLC. Published experimental FLC data obtained for different bilinear loading conditions were used to validate the theoretical work in both plane stress and general three-dimensional stress conditions. It was found that this modified MK model predicts FLC that correlate well with the limited experimental data.
The use of Hierarchical Systems (HS) technology in conceptual design of BCI is proposed in the work. Being biomechatronic by nature BCI system contains, biological (brain), computer, visual informatics (LCD, GUI), ele...
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The use of Hierarchical Systems (HS) technology in conceptual design of BCI is proposed in the work. Being biomechatronic by nature BCI system contains, biological (brain), computer, visual informatics (LCD, GUI), electronic (sensors) and executive mechanical (mobile robot) or virtual mechanical (virtual keyboard) subsystems. So, conceptual model of the BCI system being designed should contain connected systemic models of the above subsystems presented in the general formal basis. The BCI system structure, its dynamic presentation as the unit in its environment and BCI environment should be also described in this basis. Inter-level dynamics fulfilled by system-environment (e.g., brain-computer) interactions have to be taken into account by BCI Conceptual Model as well. Traditional models of mathematics and AI do not allow such a description. So, aed model of HS was chosen as theoretical basis of BCI Conceptual Model development in the work. Results of BCI detailed design and testing are also given.
In this paper, a novel 6-DOF precise parallel robot with structure of HTRT is presented. The robot is driven by six AC servo motors, including a moving platform, a base platform and six identical chains connecting the...
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In this paper, a novel 6-DOF precise parallel robot with structure of HTRT is presented. The robot is driven by six AC servo motors, including a moving platform, a base platform and six identical chains connecting the two platforms. Inverse kinematic solution, Jacobin matrix, singularities, and workspace of the end-effector are discussed. In order to achieve high accuracy, an error compensation method for the parallel robot using back propagation neural networks (BPNN) is developed on the basis of error analysis. Experimental results show that the pose accuracy of the parallel robot was improved by more than 60% after error compensation. A series of optical assemblys demonstrate that the parallel robot is suitable for performing precise manipulation.
Two-dimensional transition-metal dichalcogenides (2D TMDCs) are considered promising materials for optoelectronics due to their unique optical and electric properties. However, their potential has been limited by the ...
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This paper addresses the experimental correlations between failure mode morphologies and the chemical changes inside an epoxy-based adhesive nanomodified by carbon nanotubes. This "special" nanocomposite is ...
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