Eric Coatanea

Searching for design contradictions and conflicts with DSM Method exemplified using a case study of the EU robot competition 2010 Professor Eric CoatanĂŠa

18/06/2010

Eurobot 2010 System dynamic model Harvesting Oranges (Our)

Oranges

+

Remaining time

+ Dispending Zone (our)

Weight collected

Referee

-

Energy used (W) acceleration and

H. Tomatoes (our)

Dispending Zone (opponent)

H. Ears of corn (our)

-

Technical knowledge (Our)

+

Software complexity (lines)

Development time

moving robot

+

Control unit treatment power

Grey raised zone Beacons

+

Climb

Fixed trees

Weight robot moving robot

Static own robot

Available resources

Move

+ Budget (Our team)

+

Opponent moving robot

Match duration (t=90s)

+

moving robot

Avoid

Detection time (t)

Development time

+ +

+ +

+

Autonomy

Earns of Corn

+

+

Power required (W)

-

H. Earns of corn (Opponent)

Number of team members (Our)

+

Speed required

-

H. Tomatoes (Opponent)

Tomatoes, corns and fixed tree possible locations

-

Dispending Zone (opponent)

Tomatoes

Distance (m)

-

H. Oranges (Opponent)

-

Number of acc./dece. cycles

+

+

+ Detection signal sent

-

-

Detect Obstacle or fruit detected

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Analysis of the system of interest Construction and Analysis of the System dynamic model It is difficult to analyze the existing interactions and find the loops in such a graph!

What do we want to do with such type of System Dynamic model?

1- We would like to clarify what are the design problems that we should solve in priority?

What is a design problem?

1- A contradiction related to a performance 2- A target that cannot be attained 3- A conflict between performances

Development and manufacturing cost

Passengers and luggage

Body

Engine + transmission + tank

More E&T permits M

+ Cruising Range

-

Weight

More W constraints CD

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Analysis of the system of interest Construction and Analysis of the System dynamic model

What are the types of contradictions that we can find in a system dynamic model?

1- Several factors influencing in an opposite manner a performance parameter.

Efficient and developed educational system

Salary level +

+ +

Educated citizens

Price level of local companies products Minus factor

+

Plus factor

Contradicting factors Performance parameter

High quality products

+

Selling products

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Analysis of the system of interest Construction and Analysis of the System dynamic model

What are the types of contradictions that we can find in a system dynamic model?

2- A parameter is influencing in an opposite manner different performance parameters.

Efficient and developed educational system

Salary level

Margin

+

Educated citizens

Price level of local companies products

+

High quality products Contradicting factors Performance parameters

Plus factor

+

+

+

+

Selling products Minus factor

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Contradictions Examples

Some countries would like to have military planes forces available far from home country (possibility to have fast air support and intervention). This requires the use of special plane and boats (expensive).

Contradiction ?

Plus factor: Fast and distant air support

Minus factor: Cost (requires special expensive boats and special planes)

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Contradictions Examples One way to solve partially the contradiction consists of developing vertical take-off and landing planes Prototype: Lockheed XFV-1(tail-

sitter) Take-off and landing on the tail

Contradiction ?

Plus factor: Vertical direction of the fuselage

Minus factor: Visual control and guidance especially during landing

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Contradictions Examples Answer 1 to vertical take-off and landing contradiction

AV-8B Harrier II

One contradiction solved (Vertical take-off and landing without need for runway and visual control and guidance) but another contradiction created!

New contradiction

Plus factor: Vertical take-off and landing without runway and visual control

Minus factor: Huge energy consumption during landing and take-off (limit greatly range of the planes)

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Contradictions Examples Answer 2 to vertical take-off and landing contradiction

+

Bell/Agusta BA609

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Contradictions Definition

Contradiction: “Model of a system conflicts that puts incompatible requirements on functional properties� [M.A. Orloff, Inventive Thinking through TRIZ]

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Contradictions Some types of contradictions

- Organizational properties vs. complexity of implementation,

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Contradictions Some types of contradictions

- Function A vs. Function B (incompatibility of functions)

To provide flame (oxidizer + fuel)

To be used under water

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Contradictions Some types of contradictions

- Technical properties vs. cost,

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Contradictions Some types of contradictions

- Technical properties vs. complexity of production

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Contradictions Some types of contradictions

- Technical properties vs. complexity of use,

Autogiro

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Contradictions Some types of contradictions

Physical property A vs. Physical property B (incompatibility of physical properties),

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Analysis of the system of interest Problem formulation (system location, environment, goals, system service functions)

Architectural definition of the system dynamic model

Confirmation

Verification and validation planning

Solution Verification (verification of the viability of the model via quick sensitivity analysis)

Solution synthesis (architectural definition of the system dynamic model) Solution (system dynamic model and analysis)

Stock

Converters

Oranges

Causal link H. Oranges (Our)

Budget (Our team)

Flow Speed required (m/s)

+

Power required (W)

Time required (s)

-

Number collected (n)

If Speed INCREASE(DECREASE) then Power INCREASE(DECREASE)

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Analysis of the system of interest System dynamic model Harvesting Oranges (Our)

Oranges

+

Remaining time

+ Dispending Zone (our)

Weight collected

Referee

-

Energy used (W) acceleration and

H. Tomatoes (our)

Dispending Zone (opponent)

H. Ears of corn (our)

-

Technical knowledge (Our)

+

Software complexity (lines)

Development time

moving robot

+

Control unit treatment power

Grey raised zone Beacons

+

Climb

Fixed trees

Weight robot moving robot

Static own robot

Available resources

Move

+ Budget (Our team)

+

Opponent moving robot

Match duration (t=90s)

+

moving robot

Avoid

Detection time (t)

Development time

+ +

+ +

+

Autonomy

Earns of Corn

+

+

Power required (W)

-

H. Earns of corn (Opponent)

Number of team members (Our)

+

Speed required

-

H. Tomatoes (Opponent)

Tomatoes, corns and fixed tree possible locations

-

Dispending Zone (opponent)

Tomatoes

Distance (m)

-

H. Oranges (Opponent)

-

Number of acc./dece. cycles

+

+

+ Detection signal sent

-

-

Detect Obstacle or fruit detected

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Analysis of the system of interest Construction and Analysis of the System dynamic model

- Place the variables in a Design Structure Matrix (DSM)

On variables Influence of: variables

A A

B 1

B

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Analysis of the system of interest Construction and Analysis of the System dynamic model

- Let’s consider the following relationships, Can you build the associated DSM? Influence On:

-2

A

+1 +3

B

C

Influence (absolute)

A

0

+1

+3

4

B

-2

0

+2

4

C

0

-4

0

4

Is influenced

-2

-3

+5

B Influence of:

C

A

-4 +2

1: 2: 3: 4:

Weak influence Average influence Strong influence Very strong influence

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Analysis of the system of interest Construction and Analysis of the system dynamic model: Contradictions of type 1 and 2 - If B is a performance variable -2

A

+1 +3

B

Influence On: A

B

C

Influence (absolute)

A

0

+1

+3

4

B is influenced by contradictory influences, (Visible in column B).

B

-2

0

+2

4

B is providing contradictory influences to A and C, Visible in line B).

C

0

-4

0

4

Is influenced

-2

-3

+5

C

-4

Influence of:

+2

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Analysis of the system of interest Construction and Analysis of the system dynamic model

- Indirect influences and loops: raise the power of the matrix

What is the meaning of the value -10 in column B, line B?

A

B

C

A

0

+1

+3

B

-2

0

+2

C

0

-4

0

A

B

C

-2

A

+1 +3 C

B A

B

C

A

0

+1

+3

A

-2

-12

+2

B

-2

0

+2

B

0

-10

-6

C

0

-4

0

C

+8

0

-8

-4 +2

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Analysis of the system of interest Construction and Analysis of the system dynamic model

- By continuing raising the power of the matrix, the most influential variables are determined but also the most influenced variables

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Analysis of the system of interest Construction and Analysis of the system dynamic model: Conflicts of type 1 and 2 - Finding the conflicting loops require in this case to raise the matrix below to power 4.

Cluster 1

Influence On:

-2

A

Cluster 1

+1 +3

Influence of:

B

C

-4

-2

-2 -2 E Cluster 2

1 C l.

+1 +3 F

C l.

D -4

2

Cluster 2

A

B

C

D

E

F

A

0

+1

+3

0

0

0

B

-2

0

0

-2

0

0

C

0

-4

0

0

0

0

D

0

-2

0

0

-2

0

E

0

0

0

+1

0

+3

F

0

0

0

-4

0

0

Influence (absolute)

Is influenced

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Analysis of the system of interest Construction and Analysis of the system dynamic model: Conflicts of type 1 and 2 It is important to give names to loops in order to see if they have a real importance on the system Harvesting Oranges (Our) Oranges

Remaining time Detection time (t)

Dispending Zone (our)

+

H. Oranges (Opponent)

+

Dispending Zone (opponent)

(B) Tomato harvesting

Tomatoes H. Tomatoes (Opponent) Dispending Zone (opponent) H. Earns of corn (Opponent) Earns of Corn

Weight collected

Detection signal sent

Detect

Obstacle or fruit detected

moving robot

H. Tomatoes (our) Climb

+ H. Ears of corn (our)

moving robot

Static own robot

Avoid

moving robot

Move

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Main References for part 1 From Anticipation to Action: A handbook of Strategic prospective, Michel Godet, Dunod Editor, 1991.

System Thinking: Managing Chaos and Complexity: A platform for Designing Business Architecture, J. Gharajedaghi, Elsevier B.H., 2006.

Business Dynamics-Systems Thinking and modeling for a complex world, John D. Sterman, Irwin- Mc grawHill Editor, 2000.

Ingéniérie et intégration des systèmes, J.P. Ménadier, Hermès editor, 1998.

Inventive Thinking through TRIZ, M.A. Orloff, 2nd Edition, 2006.

Engineering of creativity: Introduction to TRIZ Methodology of Inventive Problem Solving, S.D. Savransky, CRC Press, 2000.

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Thank you Questions?

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