Conversion and selection of standard values for mechanical product configuration design features

The use of grammars in mechanical design research is growing in popularity, largely due to the ability of a grammar to concisely express a language of designs. It is natural to attempt to achieve the level of success at writing descriptive languages for mechanical devices as is seen with spatial grammars in describing architectural styles. However, the differences in representing form and function between the fields and the mechanical designer’s focus on function must impact the type of grammars that can be used in describing mechanical designs. Two grammars for mechanical configuration design are briefly described: a string grammar for the design of cordless power drills and a graph grammar for the design of rolling carts. The ability of the grammars to generate a space of machine designs is discussed. How a mechanical design grammar can provide a platform for a designer assistance tool and the strengths and weaknesses of such a tool are presented.

The ISAC RFQ consists of an 8 metre long 4-rod split ring structure resonating at 35 MHz. The rods are vaneshaped and are supported by 19 rings. The challenge of the mechanical design is the stringent, +/-0.08 mm, positioning tolerance on the four rod electrodes for 150 kW cw operation. A 1.2 metre long prototype with three full-scale modules, each comprising one ring and 40 cm of electrode, has already been built and successfully tested to fullpower. This enables us to complete the basic electrical and mechanical design for the final unit. The initial 7-ring portion of the final RFQ will be assembled first, together with an off-line source and a portion of the LEBT, so that RF parameters and beam dynamics behavior in the injection region can be tested as soon as possible. For the final RFQ the cross-section of the vacuum tank will be square, rather than circular. This will facilitate alignment of the modules and copper plating of the vacuum tank. The scope of the paper is to report the latest results from the full power tests on the prototype and to describe mechanical and RF design features including RF coupling, alignment philosophy and the copper plating technique.

Expert tutoring system for teaching mechanical engineering

This study aims to explore the key design features that support office building occupants from the adverse effects on health, well-being, and productivity (i.e., the three aspects in the WELL Building Standard). To achieve that aim, the objectives are to (1) identify the key design features that support health, well-being, and productivity; (2) compare the key design features; and (3) analyze the interrelationships between the key design features. Information from a systematic literature review and semistructured interviews with 23 office building occupants was used to develop a questionnaire survey consisting of 33 design features. Mann–Whitney U test, Kruskal–Wallis H test, normalized mean score ranking technique, overlapping analysis, and Spearman’s correlation analysis were used to analyze 206 valid responses. The findings highlighted 11 key design features that simultaneously support office building occupants’ health, well-being, and productivity. The design features are air quality, clean drinking water, comfortable artificial lighting, adjustable workstation, comfortable temperature, sufficient space, security system, safety at parking lots, cleanliness, efficiency in building services, and safe design. From these, the last six key design features are absent from the existing WELL Building Standard. The study findings provide new insights into the body of knowledge on WELL building. Industry practitioners can use the findings in designing, planning, and maintaining office buildings that support health, well-being, and productivity. Additionally, policymakers can establish an alternative rating tool for evaluating office buildings.

This paper addresses the problem of three-dimensional (3-D) waypoint tracking for a biomimetic underwater vehicle (BUV) propelled by undulatory fins: RobCutt-II. Based on the specific mechanical design and control system configuration, the RobCutt-II can perform diversified locomotion patterns, especially submerging or surfacing vertically in the water. For practical underwater operating procedures, a selective switching control for 3-D waypoint tracking is proposed. This control scheme contains a depth controller, a waypoint tracking controller, and a selector. When tracking a series of given 3-D waypoints, the RobCutt-II can switch between two closed-loop locomotion patterns, i.e., the depth control pattern and the waypoint tracking pattern. Simulations and a comparative experimental study demonstrate the feasibility and effectiveness of the proposed switching control scheme.

As for the complex operational tasks in the unstructured environment with narrow workspace and numerous obstacles, the traditional robots cannot accomplish these mentioned complex operational tasks and meet the dexterity demands. The hyper-redundant bionic robots can complete complex tasks in the unstructured environments by simulating the motion characteristics of the elephant’s trunk and octopus tentacles. Compared with traditional robots, the hyper-redundant bionic robots can accomplish complex tasks because of their flexible structure. A hyper-redundant elephant’s trunk robot (HRETR) with an open structure is developed in this paper. The content includes mechanical structure design, kinematic analysis, virtual prototype simulation, control system design, and prototype building. This design is inspired by the flexible motion of an elephant’s trunk, which is expansible and is composed of six unit modules, namely, 3UPS-PS parallel in series. First, the mechanical design of the HRETR is completed according to the motion characteristics of an elephant’s trunk and based on the principle of mechanical bionic design. After that, the backbone mode method is used to establish the kinematic model of the robot. The simulation software SolidWorks and ADAMS are combined to analyze the kinematic characteristics when the trajectory of the end moving platform of the robot is assigned. With the help of ANSYS, the static stiffness of each component and the whole robot is analyzed. On this basis, the materials of the weak parts of the mechanical structure and the hardware are selected reasonably. Next, the extensible structures of software and hardware control system are constructed according to the modular and hierarchical design criteria. Finally, the prototype is built and its performance is tested. The proposed research provides a method for the design and development for the hyper-redundant bionic robot.

To improve the animation design ability of animation aesthetics students and the teaching ability of teachers, this paper constructs an evaluation system of animation aesthetics education based on Internet+. Firstly, the feasibility of Internet+ education is analyzed, and the Kohonen grid is introduced to fuzzy classify the images and get the corresponding affiliation vector. Then the mean value method is used to fuse the two-dimensional images, and the evaluation index of animation aesthetics education is derived according to the gray value. Secondly, considering the limited capacity of the animation aesthetics education evaluation system, the principal component analysis method is used to calculate the feature values, weight percentages, etc., to filter out the range of index values and construct the evaluation system according to the main indexes. Finally, according to the scores of students’ animation works and teachers’ satisfaction before and after the platform was implemented, it was confirmed that the built platform could optimize the teaching effect. The results showed that after the teachers adjusted their teaching according to the evaluation system, the students’ work scored 90 and above, and the student’s satisfaction with the teachers increased from the highest 6.5 to 9.8, which optimized the teaching effect.

Configuration Design and Kinematics Analysis of Compound Power-Split Mechanism Using Structural Matrix Approach

The MANTIS MultimodAl system for NeTworks of In-situ wireless Sensors provides a new multithreaded cross-platform embedded operating system for wireless sensor networks. As sensor networks accommodate increasingly complex tasks such as compression/aggregation and signal processing, preemptive multithreading in the MANTIS sensor OS (MOS) enables micro sensor nodes to natively interleave complex tasks with time-sensitive tasks, thereby mitigating the bounded buffer producer-consumer problem. To achieve memory efficiency, MOS is implemented in a lightweight RAM footprint that fits in less than 500 bytes of memory, including kernel, scheduler, and network stack. To achieve energy efficiency, the MOS power-efficient scheduler sleeps the microcontroller after all active threads have called the MOS sleep() function, reducing current consumption to the μA range. A key MOS design feature is flexibility in the form of cross-platform support and testing across PCs, PDAs, and different micro sensor platforms. Another key MOS design feature is support for remote management of in-situ sensors via dynamic reprogramming and remote login.

The purpose of this study is to explore the presence of key interactive design features across Internet-based audiology rehabilitation and self-management interventions, and whether there is evidence of them mediating effects of the intervention. Adult audiology interventions relevant to this review were identified through a literature search in Google Scholar and a hand search of key journals. Four key interactive design features that have been proposed to mediate the effects of Internet-based health interventions were reported for each intervention: social context and support, contacts with the intervention, tailoring, and self-management. Five interventions were identified as representative examples of work in the field. Social context and support and contacts with the intervention were provided in most interventions, mainly through clinician guidance. Only 1 intervention utilized tailoring to personalize intervention content to individual users, but use was minimal. Self-management features were also used in all interventions but the precise nature of these features was poorly reported. Future studies should assess the optimal dose and combinations of intervention features for maximizing efficacy in audiology intervention. To be specific, the role of tailoring should be explored, which has been identified as a potential mediator of intervention outcome in the wider e-health literature.

This paper describes the steps involved in designing an epoxy potting formulation for an ignition coil. There are several key coil design features that need to be initially determined. Then a general potting formulation can be devised using in-house knowledge. The encapsulant formulation can then be optimized with in-house electrical and mechanical testing before a trial potting run.

A motor vehicle is a complex oscillatory system with a number of elasto–damping elements, the characteristics of which are in most cases of non–linear character. Due to the car's motion on the road, and also to the effects of the powertrain and the rotating elements, the vehicle performs stochastic, secondary, spatial oscillatory motion that affects the stability and comfort parameters, and may lead to fatigue of vital parts of the car, which in turn may threaten traffic safety. The negative effects of the secondary oscillatory motion of the vehicle may be reduced by way of optimisation of the characteristics of the elasto–damping elements (oscillatory parameters) of the vehicle. In the work reported in the paper, the author has modified the method of Nelder–Mead by introducing design–dependent bounds on the oscillatory parameter values. For illustration, the method was applied to the plane model of a passenger car in order to minimise simultaneously vertical oscillations of the front and rear wheels, pitch, and vertical oscillations of a partially loaded vehicle. The following values of the optimal parameters were calculated for a car with front wheel mass m1 = 55 kg, rear wheel mass m2 = 50 kg, sprung mass m = 1095 kg, moment of inertia about the lateral axis J = 1685 kgm² and axle distance L = 2.5 m: x(l) = 15049.77 daN/m; x(2) = 11946.16 daN=m; x(3) = 1954.894 daN/m; x(4) = 907.2481 daN/m³; x(5) = 495.0496 daNs/m; x(6) = 299.9992 daNs/m; x(7) = 2000.834 daN/m; x(8) = 97 1.8788 daN/m³; x(9) = 55.5049 daNs²/m²; x(10)= 60.61329 daNs²/m². These values were computed on the condition that the object function has a minimum, that the resonant frequencies of the aforementioned masses are located within the recommended bounds, and that the oscillatory parameters are within the prescribed bounds. The parameters computed provide for optimal comfort of the vehicle considered when driving on asphalt roads at high speeds of about 30 m/s.

Convergence and ubiquity are the key characteristics of tomorrows service provision infrastructures. Cloud architectures will constitute cost-efficient backbones that will support the transmission, storage, and computing of the applications contents. These architectures can be used for business, scientific, and pervasive computing purposes. The diversity of the services delivered through cloud infrastructures increases their vulnerability to security incidents and attacks. The cost and complexity reduction requirements render the design and development of protection mechanisms even more challenging. In addition, key design features such as confidentiality, privacy, authentication, anonymity, survivability, dependability, and fault-tolerance are, in some extent, conflicting. The objective of this tutorial is to present the state-of-the-art of security and explore research directions and technology trends to address the protection of cloud communications and networking infrastructures. An emphasis will be made on the collaboration of mobile devices in cloud based infrastructures. The fundamental concepts of cloud computing security will be explored, including cloud security services, cloud security principles, cloud security requirements, and testing techniques.

At a very low specific speed (VLSS), pumps normally suffer from high disk friction losses. In order to solve this issue, it can be helpful to use a different centrifugal pump design, which is not often found in the pump industry: the Pitot-tube jet pump (PTJ pump). It shows superior performance at low specific speed due to a rather unconventional working principle, described in detail in this paper. The key design feature of the PTJ pump is the (fixed) pick-up tube. Its geometry has not varied over the last decades; it is referred to in this study as “initial” or “standard” design configuration. However, optimizing the pick-up tube might lead to a considerably higher performance. Therefore, a parameterized three-dimensional (3D) computer-aided design (CAD) model is used in this study to investigate the impact of shape deformation on pump performance with the help of computational fluid dynamics (CFD). Two CFD approaches are presented and compared for this purpose: a computationally efficient approach with limited accuracy (low-fidelity method) and a more detailed, but computationally more expensive, high-fidelity approach. Using both approaches, it is possible to obtain highly efficient PTJ pumps. As a consequence, first design rules can be derived. Finally, the optimized design has been tested for various operation points, showing that the performance is favorably impacted along the complete characteristic curve.

Based on the research of motor rolling bearings of the urban rail train, we propose a kind of multi-resolution state domain (MRSD) method to identify the working condition of the rolling bearing and apply principal component analysis (PCA) method on fault classification. First, the preprocessed signal is decomposed by wavelet packet algorithm to obtain wavelet packet coefficients, and then the correlation coefficient with the original signal is calculated. On the foundation of the correlation coefficient, multi-resolution correlation entropies (MRCE) are extracted as feature parameters. Then, we utilize PCA approach to get Descartes set which represents bearing status, that MRSD, to classify the different-sourced motor bearing condition intelligently. Finally, the method is certified effectively and feasibly by the experimental result to discriminate the state of train motor bearings.