Forward Design Method Research Articles

Research on BIM Forward Design Based on Oblique Photogrammetry Reality Model

With the rapid development and steady advancement of Building Information Modeling (BIM) technology in China, traditional 2D Digital Line Graphic (DLG) data cannot visually display rich 3D spatial information, and it is difficult to meet the needs of BIM forward design. Aiming at the increasing demand for 3D spatial data in municipal project design, this paper proposes a forward design method based on oblique photogrammetry reality model. Firstly, the Quadric Error Metrics (QEM) algorithm is used to lighten the reality model. Secondly, the standard model library of municipal facilities is built in CATIA, and the lightweight reality model is integrated into CATIA for fine restoration. The refined reality model can provide BIM designers with reference to features, geomorphology, etc., avoiding unreasonable spatial planning, no external reference to model monomers, and missing model space location information. It is convenient for designers to design, display, compare and modify the scheme in the same platform to improve the efficiency of BIM design. Change the delivery form of traditional surveying and mapping data results, and encourage designers to use BIM technology for forward design from surveying and mapping, and accelerate the popularization and promotion of BIM technology in the whole life cycle of the construction industry.

Research of Forward Design Method of Contact Dynamic Seal

The development of forward design of contact dynamic seals is an inevitable way to realize the independent development of core key components based on the research results of existing rubber and plastic seals. This paper proposes a multi-index comprehensive evaluation system for sealing performance. Based on the requirements of multiple performance indexes of dynamic sealing systems, a comprehensive evaluation of multiple index functions is constructed to provide a comprehensive evaluation of the performance of rubber and plastic seals. Based on the specific design examples of air contact seals, the design process of a certain seal is explored. Finally, the article elaborates on the future work of the forward design method and its development direction.

Operation space design of microbial fuel cells combined anaerobic–anoxic–oxic process based on support vector regression inverse model

Microbial Fuel Cells (MFCs) can produce power at the same time of wastewater treatment, which is a new technique for environmental protection and new energy. An appropriate space design of operation variables is very important to improve the performance of MFC process. This paper presents a space design method based on data-driven model but not the traditional mechanism model, which is easy to accomplish in a fast and cost-effective mode. The support vector regression (SVR) forward and inverse model are deduced with the quadratic kernel function, in which the quadratic kernel function is suitable for the mathematical formula in the inversion stage. And the space design of operation variables are proposed to calculate directly from the inverse model with the effect of confidence interval when the model prediction uncertainty are considered. The proposed design method is verified in the real MFC-A2/O equipment. It is shown that the designated operation space is a narrow and effective region of the knowledge space which brackets the entire fraction of the MFC experiment space. And in general terms, the possible product quality from the designated operation space is more densely concentrated on the desired value compared to the tradition forward model design method.

Inverse design of optical elements based on arrays of dielectric spheres.

Arrays of wavelength scale scatterers are a promising platform for designing optical elements with a compact footprint. The large number of degrees of freedom in this system allows for unique and plentiful functionalities. However, the many variables also create a complex design problem. While intuitive forward design methods work for simple optical elements, they often fail to produce complicated elements, especially those involving multiple elements. We present an inverse design methodology for large arrays of wavelength scale spheres based on both adjoint optimization or sensitivity analysis and generalized multi-sphere Mie theory as a solution to the design problem. We validate our methodology by designing two sets of optical elements with scatterers on sub-wavelength and super-wavelength periodic grids. Both sets consist of a singlet and a doublet lens with one and two layers of spheres respectively designed for 1550nm. The designed NA is ∼0.33 (∼0.5) for the sub-wavelength (super-wavelength) periodic structure. We find that with the sub-wavelength periodicity, the full width at half-maximum of the focal spot produced by the singlet and doublet is smaller than that produced by an ideal lens with the same geometric parameters. Finally, we simulate a realistic experimental scenario for the doublet, where the spheres are placed on a substrate with the same refractive index. We find the performance is similar, but with lower intensity at the focal spot and larger spot size. The method described here will simplify the design procedure for complicated multi-functional optical elements and or scatterer array-based volume optics based on a specified figure of merit.

Innovation Analysis Approach to Design Parameters of High Speed Train Carriage and Their Intrinsic Complexity Relationships

In view of the problem that it’s difficult to accurately grasp the influence range and transmission path of the vehicle top design requirements on the underlying design parameters. Applying directed-weighted complex network to product parameter model is an important method that can clarify the relationships between product parameters and establish the top-down design of a product. The relationships of the product parameters of each node are calculated via a simple path searching algorithm, and the main design parameters are extracted by analysis and comparison. A uniform definition of the index formula for out-in degree can be provided based on the analysis of out-in-degree width and depth and control strength of train carriage body parameters. Vehicle gauge, axle load, crosswind and other parameters with higher values of the out-degree index are the most important boundary conditions; the most considerable performance indices are the parameters that have higher values of the out-in-degree index including torsional stiffness, maximum testing speed, service life of the vehicle, and so on; the main design parameters contain train carriage body weight, train weight per extended metre, train height and other parameters with higher values of the in-degree index. The network not only provides theoretical guidance for exploring the relationship of design parameters, but also further enriches the application of forward design method to high-speed trains.

Driver Seat Lumbar Support Adjustments System Design Based on Ergonomics Principles

As a typical man-machine interface, vehicle driver seat directly affects driver seating and riding comfort. Lumbar support of driver seat plays a particularly important role in improving driver seating and riding comfort and is usually realized by installing adjustable lumbar support, which provides stable, comfortable support for drivers with different body sizes. Traditional lumbar support has several shortcomings, such as complex structure, high cost, insufficient adjustments ranges, etc. In this work, forward design method of lumbar support with adequate design confidence level was developed, with four-way electric adjustments system. Firstly, lumbar support adjustments ranges was analyzed according to ergonomic principles. Then the concept of lumbar support adjustments mechanism was designed and the parameters of adjustments mechanism were determined including the length and angle ranges of parts, motor and spring parameters, etc. Finally, with consideration of product processing technology and manufacturing cost requirements, detailed lumbar support adjustments system structure was determined. The validated system structure parts were produced and assembled into a prototype. The prototype was tested and accepted, which showed that not only the lumbar support system met the design requirements well, but also the forward design method presented was scientific and reasonable.

Structural Feature-Based Model Templates Design for Ultra-Precision Positioning System

Ultra-precision mechanism lies in the core of ultra-precision electromechanical equipment, and is characterized by direct electromagnetic driving, air bearing supporting and ultra-precise vibration-isolation, putting a great challenge on design methodology and tools. This paper presents a model template design method which can provide effective computer aided design and engineering tools for new system design by encapsulating the design methods and design experience of ultra-precision mechanism into series of design templates. The model template contains toolkits both for forward structural design applied to new systems, and for the analysis and optimization of existing systems, as well as mathematical model and visualization tool in physical domain. The model templates are encapsulated and assembled according to the dynamical parameters and specific design parameters. Using planar electromagnetic drive structure in ultra-precision positioning system as an example, this paper discusses the design scheme of structure’s model template in detail, and introduces fast calculation method for magnetic field and visualization program, as well as forward design method for electromagnetic coil structure. Fast scheme design and analysis for ultra-precision mechanism can be achieved by using design templates.

DISPERSION FLATTENED OPTICAL FIBER DESIGN FOR LARGE BANDWIDTH AND HIGH-SPEED OPTICAL COMMUNICATIONS USING OPTIMIZATION TECHNIQUE

In this paper, design of the RII triple-clad structure as a dispersion flattened optical fiber including small pulse broadening factor as well as small dispersion and its slope applicable in broadband and fast communication is considered. The proposed optimization technique is based on the Genetic Algorithms (GA) consisting suitable fitness function for each application. The putting forward design method introduces the pulse broadening factor (σ/σ0) about 1.0016 after 200 Km propagation at the zero dispersion wavelength that is so excellent compared to the structure (1.2794) reported in [2] recently. Meanwhile, the proposed structure provides high bit rate (more than 197.8 Gb/sec at 100 Km), large dispersion length (larger than 17400 Km), uniform dispersion slope ([0.04, −0.08] ps/Km/nm2) and broad bandwidths as well as small and uniform dispersion (smaller than 2.02 ps/Km/nm) at [1.55–1.7]μm wavelength interval Corresponding author: M. Savadi-Oskouei (morteza savadi79@yahoo.com).

3311 Pro/Eを用いたコンピュータハードディスクブラケットのプレス金型のアセンブリ設計

This paper introduces briefly the technique route of assembly design of press for a bracket of computer hard disk by using the Pro/E software platforms, puts forward assembly design method for the press according to the structure characteristics of the bracket by applying Pro/E assembly design technique. It greatly raised the design efficiency and design accuracy of the compound mold assembly design and the bending mold assembly design. The result provides foundation for the numeric control process manufacturing of the press.

A straight forward and flexible design method for complex data-base management systems

Human manipulation of objects generally includes handling knowledge concerning these objects. Knowledge handling requires in its turn the manipulation of documents. Document manipulation will be shown to require information transfer, storage and retrieval. When large amounts of information are to be stored and retrieved, the need arises for the creation of information storage and retrieval systems. This paper presents a description and design method for such systems. The method is based on a modelling technique. A logical system model will be shown to be derivable from the general objectives and the collection of tasks set for a system. It will then be explained how the physical realization of an information storage and retrieval system can be derived from its logical model taking account of hard- and software properties of the computer system and the programming language to be used. Finally a detailed outline will be presented for a design procedure. The practical applicability of this procedure has been proved during the design of several large data-base management systems.