ME Seminar 18. jaanuar 2006

Lembit Roosimölder

Aksioomidest lähtuv projekteerimine

Axiomatic Design

ME Seminar 18. jaanuar 2006

Aksioomidel põhinev konstrueerimine (MIT)

ME Seminar 18. jaanuar 2006

General Axiomatic Design

Concepts

• Understand their customers' needs • Define the problem they must solve to

satisfy these needs • Create and select a solution • Analyze and optimize the proposed solution

• Check the resulting design against the

customers' needs

ME Seminar 18. jaanuar 2006

Axiomatic DesignCustomer Domain The benefits customers seek

Functional Domain Functional requirements of the design solution

Physical Domain Design parameters of the design solution

Process Domain Process variables

Functional requirement

Functional requirements (FRs) are a minimum set of independent requirements that completely characterize the functional needs of the design solution in the functional domain.

Constraint Constraints (Cs) are bounds on acceptable solutions.

Design Parameter Design parameters (DPs) are the elements of the design solution in the physical domain that are chosen to satisfy the specified FRs.

Process variable Process variables (PVs) are the elements in the process domain that characterize the process that satisfies the specified DPs.

ME Seminar 18. jaanuar 2006

Axiomatic DesignThe output of each domain evolves from abstract concepts to detailed

information in a top-down or hierarchical manner Valdkondade väljundid arenevad abstraktsetest ideedest kuni üksikasjaliste

kirjeldusteniTwo design axioms provide a rational basis for evaluation of proposed solution

alternatives and the subsequent selection of the best alternativeKaks järgnevat konstrueerimise aktsioomi on ratsionaalseks aluseks

lahendusvariantide hindamiseks ja valikuksThe first axiom is the independent axiom, and it states that a good design

maintains the independence of the functional requirementsEsimene, sõltumatuse aktsioom ütleb, et lahend on hea vaid siis, kui on tagatud

funktsionaalsusnõuete sõltumatusThe second axiom is the information axiom and it establishes information

content as a relative measure for evaluating and comparing alternative solutions that satisfy the independence axiom

Teine, informatsiooni aktsioom ütleb, et info sisu peab tagama selliste lahendusvariantide võrdlemise ja hindamise, mis vastavad esimesele aktsioomile.

ME Seminar 18. jaanuar 2006

Axiomatic Design

• With QFD (Quality Function Deployment, "the voice of the customer"), designers gather information from customers about their requirements and the relative importance of each. This information helps the designer to choose which FRs must be present and which may be safely ignored.

• When a designer has selected an FR and wants to identify alternative DPs to achieve it, TRIZ (the theory of inventive problem solving) can be helpful in generating alternatives.

• After choosing a DP to satisfy an FR, the designer uses robust design to optimize the design of this particular DP, which helps to reduce the information content of the design.

• The designer follows the axiomatic design process and uses the various techniques when appropriate. Axiomatic design helps the designer avoid mistakes such as unknowingly attempting to optimize a coupled design.