Design work (Yibo Sun)

SEP760: Final Exam (Yibo Sun)

Yibo Sun - McMaster UniversityCreated: 12-DEC-16 Last Modified: 15-DEC-16

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SEP760: Final Exam (Yibo Sun)


Contents

Design process



Problem finding process:

For the background research process, I read some reports about statistical study on

bicycle locks. Ask bicycle users questions from the following questionnaire:

Do you think your lock is effective against theft?

With this in mind have you taken any further action to secure your bicycle? If so

what are they?

Do you ever find any of the following a problem?

1. Handling your lock when using?

2. Keys

3. Lock maintenance

4. Using in a wet and or cold environment

5. Carry with bike

6. Size

7. Shape

8. Weight

9. Other (Please specify)

Please list any objects or locations that you have had difficulty locking your bike to

with the hardest first?

Would you benefit from a lock that was a permanent part of your bicycle frame?

SEP 760: Design Thinking

Final ExamCreated by : Yibo Sun



Statistical analysis on lock typeshttp://tram.mcgill.ca/Research/Publications/Cycling_theft.pdf

Major

problems found from considering interview, observation, and research:

1. Parts of the bicycle are often stolen.

2. Frozen surface could hurt skin of hands in the winter time.

3. Lock couldn't fit locking spot.

4. Often lost lock itself.

5. Not convenient to carry with bike.

References:

http://tram.mcgill.ca/Research/Publications/Cycling_theft.pdf

http://www.bikeradar.com/forums/viewtopic.php?t=12749345

https://www.surveymonkey.com/r/FDQSJ29?sm=ls7Imja9UWR3Tsaizy%2bSAA%3d%3d

http://environment.uwaterloo.ca/research/watgreen/projects/library/s98bikesecurity.11

8.pdf

Problem solving process:

















https://www.surveymonkey.com/r/FDQSJ29?sm=ls7Imja9UWR3Tsaizy+SAA==







http://environment.uwaterloo.ca/research/watgreen/projects/library/s98bikesecurity.118.pdf








According to the problem finding process, major problems has been analyzed and considered. A

objective tree with constraints was then generated to better process the design ideas. The main

objective is to find a way to secure a bicycle, not necessarily a bicycle lock.

Objective tree with constraints

After

that, a metrics for each of the lowest level objectives as well as the constraints from the

objective tree was listed. Related values and ranges were then selected from research. These

values were justified by making compairation with samilar products in the market. In addition,

there are multiple bicycle lock ratings that has been used in the market, one standard was

selected, because it was only used to compare diffferent alternatives for this design process. If

the standard is uniform, there should be no problem of it.



Matrics

Material radar chart https://www.researchgate.net/figure/272724636_fig4_Figure-4-Radar-charts-of-three-types-of-titanium-alloys-TC4TC11-and-TC17



Material strength and toughness charthttp://www-materials.eng.cam.ac.uk/mpsite/interactive_charts/strength-toughness/NS6Chart.html



Bicycle lock rating scalehttp://www.kryptonitelock.com/en/proper-lock-up/bicycle-lock-up.html

Three

designs were then generated using a morph chart. "The morphological chart is a

method to generate ideas in an analytical and systematic manner. Usually,

functions of the product are taken as a starting point. The various functions and

subfunctions of a product can be established through a function analysis (see

‘Function Analysis’ in this section). However, function analysis does not guarantee

that all the relevant (sub) functions are identified. Often a number of solutions to

these (sub) functions are already known, while others are thought up by yourself.

These solutions will form the components in the morphological chart. The

morphological method thus yields a matrix of functions and components."

Reference:

http://www.wikid.eu/index.php/Morphological_chart



http://www.wikid.eu/index.php/Morphological_chart

Morph chart



Alternative 1



Alternative 2



Alternative 3

A

final design was selected using a decision matrix populated with values and computed

using the metrics. Metrics are listed on the left column of the matrix, and each criteria

was assigned a weight based on how important are they considered in the design

process. 3 alternatives were then analyzed individuly. The raing was given to each

alternative based on their design concept and specification. The score is actually the

weighted total for each design by multiplying weight of criteria and rating of the

alternative. Rating is defined as 1-5, and the full mark of the score is 5. Alternatives were

then ranked by their score, and the best alternative was selected as the final design.



Decision matrix

Selected design:

The lock is part of the bicycle frame.

Two stretchable parts with lightweight.

Lock body material is titanium, and the surface is covered by robber.

security level is estimated as 7.

Designed operation time within 5 seconds.

Doesn't require any specific locking spot.

Spring installed to help push beams aside.

Key could be stored in safety hat.



Selected design



Beam detail

Spring detail

Benefit of the design (value creation):

For manufacturer:

create opportunity for job market.



Lead business growth.

For bicycle users:

Reduce the risk of losing wheel and other parts of the bicycle.

Protect hand skin from cold surface (enhance health and safety).

Reduce the operation time and time looking for locking spots (time

efficiency).

Increasing the reliability of lock (won't be lost).

Make it more convenient to carry with bike.



Design work (Yibo Sun)

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