Оккам - Research and Innovations
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Home "When you have two competing theories that make exactly the same predictions, the simpler one is the better."
Welcome to Okkam, the innovations venture for Science, Technology and Innovation in the Movement Research and Development!Our Vision Our Mission Okkam research includes:
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Morphological approach with "Okkam" for innovative Engineering Systems (ES)Links --> Rakov, D., .Timoshina A. (2010): Structure synthesis of prospective technical systems. IEEE Aerospace and Electronic Systems Magazine. - : Feb. 2010. - Volume: 25 -Issue: 2. 4 - 10. One of the key stages in aircraft engineering systems process is the conceptual design phase. Conceptual design is considered to be the most difficult phase of engineering design, with success dependent to a great extent on the expertise of a designer. Automation of some aspects of this phase would be of immense practical benefit [1]. During this phase, the designer must devise an initial design that incorporates ‘‘working principles’’ or physical solutions to all the ‘‘essential’’ features of the problem, and which has been evaluated to be acceptable and feasible [2]. This is the phase of the design process ‘‘that makes the greatest demands on the designer, and where there is the most scope for striking improvements and where the most important decisions are taken’’ [3]. Conceptual design is a fundamental and indispensable forerunner to further detailed design. Not only is it well known that a design concept is the overwhelming factor influencing the product life-cycle cost and level of innovation; but an excellent detailed design based upon a poor and inappropriate concept can never compensate for the inadequacy of that concept. Conceptual design is an early phase in the design process, which involves the generation of solution concepts to satisfy the functional requirements of a design problem. There can be more than one solution to a problem; this means that there is scope for producing improved designs if one could explore a solution space larger than is possible at present [4]. As shown in Fig. 1, design uncertainty is the largest for entirely original designs and decreases during design [5].
The project costs are minimal on a conceptual design stage, but importance of accepted solutions is maximal. Therefore the conceptual design is the basic phase of design process (Fig.2).
For creation of competitive and innovative products it is typically necessary to synthesize from 50 up to 150 new engineering solutions. [6]. In [7] 3 levels of optimization are examined at creation of new ES. Performance characteristics of projected systems at the third level of optimization can be improved on the average of 10-15% (Fig. 3). At level 1 and 2 characteristics are improved on the average of 30-35 %, and sometimes more. The higher the level of optimization, the more is the effect of optimization. In engineering practice there is usually no way allowing the choice of an optimum engineering solution based on conditions of the technical project at once.
Subject of search in structural synthesis is achievement of some compromise levels for lines of inconsistent criteria. The sequence of computing operations for finding of an optimum algorithm for the design calculation is displayed by an objective function. This function does not correspond to the basic requirements of theoretical methods of optimization (including genetic algorithms). The objective function is discontinuous, exists in operator notation, it is not based on analytic forms, is not differentiable, not unimodal, not separable and also not additive. It is impossible to model analytically a hyper surface of objective functions and to predict their change on an increment of variables. Instead of step-by-step promotion in space of attributes area-scanning searches with use of clusters seem to be more efficient. For the problems decision of structural synthesis there are two groups of methods - morphological and heuristic. Heuristic approaches yield unstable results and are subjective. Morphological analysis is a method developed by F. Zwicky for exploring all the possible solutions to a multi-dimensional, non-quantified problem complex [8]. Zwicky applied this method to such diverse tasks as the classification of astrophysical objects and the development of jet and rocket propulsion systems. More recently, morphological analysis has been extended and applied by a number of researchers in the U.S.A and Europe in the field of future studies, engineering system analysis and strategy modeling [Odrin, 1998; Coyle et al., 1994; Rhyne 1995; Ritchey 1997, 2003, 2006; Stenstroem & Ritchey 1999; Akimov, 2005]. The morphological approach serves as a standard when new systems are being designed [9,10]. The basic problem of morphological methods is the so-called “damnation of dimension”, which means, that rapid generation of an enormous set of variants is relatively simple, but selection of the best variants is very difficult [11]. The disadvantages of morphological methods are as follows: · Labor-intensive selection from a set of variants and · Impossibility of search and analysis of all variants. To remove the aforementioned disadvantages a methodology of the structural synthesis of engineering systems (SSES), based on the system, morphological, and cluster approach has been developed. Using the methodology, different engineering systems, mostly in the area of Aeronautics, Astronautics, and Ecology, have been studied [12,13,14] (Fig.4). Fields of generated variants for Reentry vehicles [15,16] (Fig.5) is given below.
Figure 4: Areas of the SSES application
[1] S. Potter, S.J. Culley, M.J. Darlington, P. K. Chawdhry: Automatic conceptual design using experience-derived heuristics. Research in Engineering Design. Volume 14, Number 3. Springer, London. 2003. P.131-144. Conclusions
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