2 .1 P RODUCT M ODELING2 .2 V IRT UA L P ROTOT YPING

ENT 452 : RA P ID ENG IN EERIN GRUSLIZA M DA UD

Product Modeling and Virtual Prototyping

2.1 Product Modeling

This section will help to answer the following questions:

Is there any systematic way to

model a product or prototype?

How to organize all aspects of the model

design phase?

How to choose which model type to use, formal or informal

models?

2.1 Product Modeling

1. Product Model is a model of a product metric that is representation, simplification or estimation of a product’s realization to aid in making product decisions.

2. To establish a model, a wealth of data needs to be collected to develop analytical models, including customer needs, PDS, the house of quality, chosen product concepts, etc.

2.1 Product Modeling

Model Preparation: To map and relate the customer need/weight to the

product function

Model Prioritization: To identify the functions that relate most strongly to

the customer needs

Model Quantification: To choose the metrics or engineering characteristic that may

be used to quantify the material, energy or signal flows for these functions. To identify

target values for these metrics based on benchmarking.

House of Quality (QFD)

House of Quality (QFD)

House of Quality (QFD)

2.1 Product Modeling

Informal model

•A designer’s interpretation of description of customer needs, engineering characteristics, manufacturing requirement, etc.

Formal model

•It constructs a computable or analytical model of the design problem. The goal is to find the optimal design variables to satisfy design requirement.

2.1 Product Modeling INFORMAL MODEL

What is the problem really about?

What implicit expectations and desires are involved?Are the customer’s needs,

requirements, and constraints truly appropriated?

What characteristic or properties must the product have/must the product not

have?What are technical conflicts inherent in the design task?What aspects of the design task should be quantified

now?Are there any other features

of the product?

2.1 Product Modeling (example: Retractable earphone)

What is the problem really about?

What implicit expectations and desires are involved?

Are the customer’s needs, requirements, and constraints

truly appropriated?What characteristic or properties must the product have/must the

product not have?

What are technical conflicts inherent in the design task?

What aspects of the design task should be quantified now?

Are there any other features of the product?

When removed, always get caught and tangled

Usability, comfort, portability, quality, cord length

Small and light

Comfortable, easy to operate/bulky, awkward

A coil of spring to wind/unwinding the cord, the spool diameter must be

largeTotal length of the cord, retracting device length and acceptable

tension.

Aesthetic

2.1 Product Modeling (example: Binder clip)

1. Interview

2. Present cost scenario

3. Cost breakups

4. Technical questioning

5. Mission statement

6. Technical evaluation

7. Material selection

8. Manufacturing technique used

1.together papers, official, 50-100 pieces, easy, compact, average

2.Not many binder can hold more than 150 pieces, available cost about RM 3.50 each,

plastic and Al spring3.Assembly, transportation, design costs,

material cost, packaging, advertising, profit

4.Basic use, customer needs, company aim, product operation/usage

5.Hold 150 pieces, easy to use, not too stylish, formal, use metal to increase

product life cycle

6. thickness, mouth open, material high spring constant, torque compression.

7. Longevity, steel with powder coating

8. Forging, bending, powder coating

2.1 Product Modeling FORMAL MODEL

•Identify a material, energy, or information flow associated with each effect of the product concept.•The flow is the possible interaction of the product with its usage environment.

Step 1:Identify a flow

•Identify a balance relationship for the flow to find the equilibrium equation to model the system.

Step 2:Identify a balance

relationship

•Recognize the boundary conditions of the product concepts. How its is loaded, how does it interact as a system in environment including human interface. What are the input and outputs across the boundary, and its limit ranges.

Step 3: Identify a boundary for the

balance relationship

2.1 Product Modeling FORMAL MODEL

•Convert the balance relationship to a mathematical form by assigning geometric variables, material property constants to formulate a set a equations. Applied m mathematics and science are required. •A number of assumptions and simplifications are needed.

Step 4:Formulate an

equation for the balance relationship

•Use the model to explore design configuration options

Step 5:Design

exploration

2.1 Product Modeling FORMAL MODEL: PRODUCT MODEL FOR JAR OPENER

Step 1:Identify a flow

Step 2:Identify a balance

relationship

Step 3: Identify a boundary for the

balance relationship

Customer need Flow

Easy to store Kitchen

Easy to hold Handle

Receive the torque Force

Increase the torque Force

Grasp the jar tops Jar tops

2.1 Product Modeling FORMAL MODEL

•F1=F sin θ•F2=F cos θ•Ff=F1µ=F sin 赕Ff·L1=F2·L2

Step 4:Formulate an

equation for the balance relationship

•With this model, the working principles of this kind of opener is known and this product can be improved.•The length of L2 needs to be optimized in order to get the best effect of increasing torque and facility to be operated.

Step 5:Design

exploration

L2

L1

FfF2

θ F

F1

2.1 Product Modeling

Solid model

Surface model

Wire frame

2.1 Product Modeling

CAD data

2.1 Product Modeling

FEA

Inertia

Fatique

Mass prop.

dynamicLinear and non linear

Heat transfer

Mold flow

2.2 Virtual Prototyping

Virtual prototyping is combining the virtual environment with engineering design to mallow designer or engineer to play an active role in the design sensitivity and optimization process.

Virtual reality is a system that provides a non-real environment but gives the feeling of real sense.

2.2 Virtual Prototyping

Robotic part handling

Parts in fixture

Parts on conveyor

Components interaction

2.2 Virtual Prototyping

Observe

Parts going jammed in

transfer line

Robot can successfully pick

part in right orientation

Modular fixture can firmly

clamped for machining

Redesign consideration for cost

down purpose and quality /functional

improvement

2.2 Virtual Prototyping

Clearance

Friction

Chamfers

Parts Feasibility

2.2 Virtual Prototyping

1. Observe a visual representation of the

virtual parts and equipment involved

2. Can interactively manipulate a virtual part or equipment through haptic

interface devices according to the force and motion

3. Can feel the objects and hear the sounds

from virtual work cell

Tutorial and Quiz

T1•Prepare the Customer Attributes CAs according to Primary, Secondary and Tertiary level. Case study product: Manual Inflator (11-12/8/08)

Q1•Develop a product model (informal or formal model) for mechanical pencil (12/8/08)