SELF-ORGANIZED SEMANTIC FEATURE EVOLUTION FOR AXIOMATIC DESIGN

Aiming at the problem existing in the computer aided design process that how to express the design intents with high-level engineering terminologies, a mechanical product self-organized semantic feature evolution technology for axiomatic design is proposed, so that the constraint relations between mechanical parts could be expressed in a semantic form which is more suitable for designers. By describing the evolution rules for semantic constraint information, the abstract expression of design semantics in mechanical product evolution process is realized and the constraint relations between parts are mapped to the geometric level from the semantic level; With semantic feature relation graph, the abstract semantic description, the semantic relative structure and the semantic constraint information are linked together; And the methods of semantic feature self-organized evolution are classified. Finally, combining a design example of domestic high-speed elevator, how to apply the theory to practical product development is illustrated and this method and its validity is described and verified. According to the study results, the designers are able to represent the design intents at an advanced semantic level in a more intuitional and natural way and the automation, recursion and visualization for mechanical product axiomatic design are also realized.

Method for Functional Design of Axiomatic Design Based on Connections

Axiomatic design（AD） is a popular design method,and satisfying the independence axiom is the basis of AD.However,AD doesn＇t provide methods to decompose functions then keep them independent and to handle coupled design.A few of ways of handling coupled design are mainly passive resolutions when coupled design exists,but not efficient to each product design.Hence,this paper presents an innovative approach to design and decompose functions of complex products based on functional connections,aiming at actively avoiding functional coupling.By contrasting with component networks,four kinds of relations among functions are identified,including spatial,energy,material,and information connection.Then the definitions of these relations and the dominant connection are given.Based on the definitions,the principles of functional decomposition and design are developed,in which each non-leaf function is broken into sub functions centered on its dominant connection with avoidance of functional cross and coupling,and sequentially satisfies the independence axiom.Then the operational flow of the proposed approach is constructed.Determining the dominant connection of a function,decomposing the function into sub functions in terms of the dominant connection and reverse examination and optimization are planed as the core steps in each zigzagging.Input process output（IPO） analysis is introduced to obtain the dominant connection of a function,some rules for examining and optimizing the decomposition results reversely according to oriented object theory are presented as well.An illustrative example about the pouring function of squeeze casting equipments presented demonstrates how to use the proposed approach,and indicates its effectiveness.The proposed approach expands the principles of AD,constructs a guidance policy for independent functional design of complex products based on AD,and can help decrease or actively avoid coupled design and improve design efficiency.

Axiomatic Design of Micro Quartz Rate Sensor

Quartz rate sensors （QRS） made out of one single piece of quartz crystal are inertial devices which can be used for general rate control, stabilization, automotive and aerospace/defense markets, etc. The mechanical design of the QRS has been investigated based on axiomatic design. The axiomatic design matrix of the mechanical structure of Coriolis Vibratory Gyroscopes （CVG） has been proposed. The mechanical function of QRS is divided into three Function Requirements （FR） , i. e. , FR1 is the drive mode, FR2 is the sense mode, FR3 is a coupled connection where the Coriolis force can couple the two modes with a term proportional to the rotational rate. A new QRS which is easy to be fabricated has been put forward. Furthermore, the new QRS indicated that the axiomatic design is a help to functional design of products.

Deriving invariant checkers for critical infrastructure using axiomatic design principles

Cyber-physical systems(CPSs)in critical infrastructure face serious threats of attack,motivating research into a wide variety of defence mechanisms such as those that monitor for violations of invariants,i.e.logical properties over sensor and actuator states that should always be true.Many approaches for identifying invariants attempt to do so automatically,typically using data logs,but these can miss valid system properties if relevant behaviours are not well-represented in the data.Furthermore,as the CPS is already built,resolving any design flaws or weak points identified through this process is costly.In this paper,we propose a systematic method for deriving invariants from an analysis of a CPS design,based on principles of the axiomatic design methodology from design science.Our method iteratively decomposes a high-level CPS design to identify sets of dependent design parameters(i.e.sensors and actuators),allowing for invariants and invariant checkers to be derived in parallel to the implementation of the system.We apply our method to the designs of two CPS testbeds,SWaT and WADI,deriving a suite of invariant checkers that are able to detect a variety of single-and multi-stage attacks without any false positives.Finally,we reflect on the strengths and weaknesses of our approach,how it can be complemented by other defence mechanisms,and how it could help engineers to identify and resolve weak points in a design before the controllers of a CPS are implemented.

New Hybrid AD Methodology for Minimizing the Total Amount of Information Content:A Case Study of Rehabilitation Robot Design

Converting customer needs into specific forms and providing consumers with services are crucial in product design.Currently,conversion is no longer difficult due to the development of modern technology,and various measures can be applied for product realization,thus increasing the complexity of analysis and evaluation in the design process.The focus of the design process has thus shifted from problem solving to minimizing the total amount of information content.This paper presents a New Hybrid Axiomatic Design(AD)Methodology based on iteratively matching and merging design parameters that meet the independence axiom and attribute constraints by applying trimming technology,the ideal final results,and technology evolution theory.The proposed method minimizes the total amount of information content and improves the design quality.Finally,a case study of a rehabilitation robot design for hemiplegic patients is presented.The results indicate that the iterative matching and merging of related attributes can minimize the total amount of information content,reduce the cost,and improve design efficiency.Additionally,evolutionary technology prediction can ensure product novelty and improve market competitiveness.The methodology provides an excellent way to design a new(or improved)product.