MSD I SMART CANE INTEGRATION SYSTEM SYSTEMS DESIGN PHASE REVIEW P15043 October 2, 2014

MSD I SMART CANE INTEGRATION SYSTEMSYSTEMS DESIGN PHASE REVIEW

P15043

October 2, 2014

Agenda

Problem Statement Background Team Update Updated Customer Requirements Updated House of Quality (HOQ) System Analysis Concept Selection Proposed Concept Risk Assessment Patents Lessons Learned Next Steps

10/2/2014

P15043 Systems Design Review

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Problem Statement

Current State: The blind face navigational and safety challenges Current audio feedback solutions have several

shortcomings P14043: Prototype not fully functional; extremely fragile

Our Mission: Design an assistive device for use by the blind and deaf Integrate existing concepts from P14043 Improve on P14043’s design Assembly process to be performed by blind workers

10/2/2014P15043 Systems Design Review

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BackgroundP14043: Smart Cane

Pros: Proof of concept Effective haptic feedback Low manufacturing cost

Cons: Fragile/weak structure Sensor system not

integrated Loose electrical connections Bulky microprocessor Excess of small parts

Rotating handle section to

provide haptic feedback

10/2/2014P15043 Systems Design Review 4

Team Update


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2nd customer interview Tour of ABVI facilities Meetings with individual stakeholders Team building activity

It was aMAZEing!

Updated Customer Requirements


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*Customer requirements are ranked by importance

Updated HOQ


Pareto


Pareto Analysis

25% of the engineering requirements contain 66% of the weight for this project

Top Four Items Provide 90 degree detection range in front

of user Signal detection of obstacles via haptic

feedback (horizontal and vertical motion in handle)

Horizontal detection range of 6 feet Prototype cost under 1,000 USD


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Functional Decomposition


10

Concept Generation


Morphological Analysis

Concept Generation

Pugh Analysis

Concept Proposal

Morph AnalysisSub-function /

Cane Component

Collapse CaneHandle Only -The rest of the cane

collapses Wired Together Pressure Fit Folding with hinges Screw Connections

Sensor Location In Cane Handle On Cane Shaft On Hand

Provide Power Rechargeable

BatterySolar Outlet

Provide Feedback to

UserRibbon/Wrist Twist Twisting Handle

Roller (Bearing) P14043

Drill Button/Whack-A-Mole

Wristbands separate from cane

Detect Objects Sonar Optical Ultra-Sonic Infrared

Weight Concentration

In handle Over Whole Cane

Concept Ideas


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Concept 1Concept 2Concept 3

Concept 1: Roller In Handle

Pros: Beta Phase

(Continued from last year)

Concerns: User feedback

awareness User learning curve Versatile cane handling


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Concept 2: Actuated Buttons In Handle

Pros: Easy learning curve Feedback awareness Potential to have

versatile cane handling

Concerns: Handle must be designed

carefully to ensure versatile cane handling


Concept 3: Wrist Bands

Pros: Very versatile cane

handling Easy learning curve

Cons: Potentially costly Potentially time consuming Multiple separate parts Possible to switch

wristbands and get incorrect feedback


Pugh Selection Matrix

Number Selection Criteria Datum P14043 Idea 1

Roller in handle

Idea 2Actuated Buttons

in handle

Idea 3Wrist Bands

1 Low Cost 0 0 -

2 Doable in 2 Semesters 0 0 -

3 Reliability/Consistency 0 0 0

4 Durability + + +5 Versatile Cane Handling 0 0 +6 Light Weight 0 0 07 Manufacturability + + +8 Easy Learning Curve 0 + +

9Minimized number of separate components

0 0 -

10Flexibility of where to put sensors

+ + +

11 Feedback Awareness 0 + +

12 Collapsibility + + +

Sum + 's 0 4 6 7

Sum 0's 0 8 6 2

Sum -'s 0 0 0 3


Pugh Selection Matrix

Number Selection Criteria Idea 1Roller in handle


in handle

Idea 3Wrist Bands

1 Low Cost 0 DATUM -2 Doable in 2 Semesters + -3 Reliability/Consistency 0 04 Durability 0 05 Versatile Cane Handling 0 +6 Light Weight 0 07 Manufacturability + -8 Easy Learning Curve - 0


0 -


0 0

11 Feedback Awareness - +12 Collapsibility 0 0

Sum + 's 2 0 2

Sum 0's 8 0 6

Sum -'s 2 0 4

Number Selection Criteria Idea 1Roller in handle


in handle

Idea 3Wrist Bands

1 Low Cost + + DATUM2 Doable in 2 Semesters + +3 Reliability/Consistency 0 04 Durability 0 05 Versatile Cane Handling - -6 Light Weight 0 07 Manufacturability + +8 Easy Learning Curve - 0


+ +


0 0

11 Feedback Awareness - -12 Collapsibility 0 0

Sum + 's 4 4 0

Sum 0's 5 6 0

Sum -'s 3 2 0


Comparing our 3 concepts to better understand their advantages with respect to each other

Proposed Concept


Concept 2 Feedback through actuated buttons on handle

What we like about it:• Easy to interpret feedback

• Direction is clear (rollers are not intuitive)

• Not significant internal design deviation (motors, wiring)

• Feasible in two semester schedule• Does not require expensive technology

(Bluetooth)

Trade-offs• More moving parts • Less flexibility with user grip

System Architecture

BatteryMicro

Processor

Sensors

Haptic Feedback

(User Interface)

Motor

Environment


Feasibility Analysis

Key Topics (Potential faculty correspondence) Feedback to the user (Tom Oh) Sensor location (Tom Oh and Kolodziq / Wellin) Cane weight (Matt Marshall) Cane collapsibility (Matt Marshall)


Question Consideration Type

How will the user be effected if the feedback is delayed or not working (connection error/disconnect)?

Analysis

Will the cane be able to be easily collapsed or reassembled in one minute or less? Benchmarking

How quickly must feedback be relayed to the user in order to allow them the ability to comfortably react?

Analysis

How does user height affect sensor height on the cane? Analysis

Will the additional weight of the cane have a significant negative impact on the user?

Analysis

If the sensors are placed lower on the cane will it affect the user more, vice versa? Analysis

Risk Assessment Risk Item Effect Cause

Likelihood

Severity

Importance Actions to Minimize Risk

General

1 Battery contact is compromised Loss of power Deflection of wire connection 2 3 6Make sure all components that house wires

are rigid and secure wires sufficiently for cane movement

2 User Muscle Fatigue Pain/discomfort to user •How hand grips on handle•Weight distribution of cane 2 2 4 Ergonomics considered in design

3 Over heating Damage to systemHarm to user Insufficient heat dissipation 1 3 3 Perform thermal analysis

4 Cane malfunction No feedback delivered to user Component malfunction or damage 1 3 3 Design for redundancy

5 Misplaced parts User frustration Multiple unconnected in the system 2 1 2

•Make system all one piece•Create a way separate components can be

stored together when not in useSensors

6 Sensors relay incorrect information to feedback

Confusion and/or danger to user

•Sensor malfunction•Broken connection

•Problem with program1 3 3 Test prototype extensively

7 Sensors hit obstacles when cane is sweeping

•Damage to sensor•Shift in sensor position

•Sensor falls offLocation of sensors on the cane 2 2 4 Attach sensors in the top region of the cane

8 Sensors get dusty/dirty Malfunction Environment encountered 1 2 2 State in user manual that sensors should be cleaned frequently

Haptic Feedback

9 Water damage Ruined components Not waterproof 2 3 6 •Minimize openings •Put waterproof cover over feedback

10Loss of haptic motion (when signal is sent from sensors, feedback does not

respond with motion)Feedback not given to user

•Disconnection of feedback mechanism and motor

•Burnout of motor2 3 6

•Sufficiently secure roller to motor •Do analysis to make sure torque is not too

high for motor

11 Haptic motion is unclear and not intuitive

•User confusion•Learning curve to use cane Haptic motion design 2 2 4 Do thorough testing to make sure haptic

feedback relays information clearly to users

12 Feedback is obstructed by clothing or jewelry (ex. Gloves) Decreased feeling of feedback Location where feedback comes in

contact with the user 1 2 2 Brainstorm ways to minimize clothing/jewelry obstruction


Risk Mitigation

Items such as 4 and 10 can be reduced or eliminated through mindful design 4: Cane malfunction 10: Loss of haptic feedback

We will actively aim to reduce the number of risks as the project progresses Severity to project outcome will increase if

not addressed


Patents

Patent No. US 8,077,020

Method and apparatus for tactile haptic device to guide user in real-time obstacle avoidance.

By Gary Behm and Richard Mering


Patents cont.

Patent No. US 7,706,212 B1

Mobility director device and cane for the visually impaired

By Terry Campbell

10/2/2014P15043 Systems Design Review24

Patents cont.


Environment sensor that conveys information about objects in the vicinity of the visually impaired user.

By Thomas Leberer


Patents cont.


Mobility device and method for guiding the visually impaired

By Terry Campbell and Eric Karich


Lessons Learned

Pugh chart and feasibility analysis helped to: Expose areas to address in our risk

assessment and mitigation plan Highlighted gaps in our expertise

Customer communications are critical in the design process

Better coordinate project work with team member’s schedules


Schedule – Phase III


P15043 Systems Design Review

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Next Steps – High Level

10/2/2014

Select system design based on phase II review

Test Plan System Level High risk sub-systems

Proof of Concept (POC) Design review with appropriate RIT

faculty

Questions


Feasibility Analysis: Question 1

How will the user be affected if the feedback is delayed or not working (connection error/disconnect)?

Assumptions: User uses cane regularly User checks to makes battery is charged Battery is on Connections are completely plugged in

Problem: If cane is not working properly, there is no mechanism to communicate this back to the user

Conclusion: Feedback should be put in the cane to alert user that there is a connection error/disconnect.


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Will the cane be easy to collapse or reassemble in one minute or less? Assumptions

User understands how the cane should be folded before performing this task

User has the motor skills necessary to perform the task User is in a reasonable environment to be performing this task (i.e.

No extreme temperatures) No tools will be required for the task

Benchmarking Collapsible Canes

Option Estimated Time

Notes

1. Folding (elastic)

7 seconds Time would be much longer for a non-experienced user

2. Push button to open

3 seconds Assumes one connection

3. Cane couplers 2 seconds Time is per connection10/2/2014P15043 Systems Design Review 32

Feasibility Analysis: Question 2Will the cane be easy to collapse or reassemble in one minute or less?

Figure 3. Cane Couplers (2 sec per connection)

Figure 1. Folding Cane (7 sec)

Figure 2. Push Button Cane


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How soon must feedback initiate to allow time for user to react?Assumptions:

User will be traveling at an average of 3 mi/hr (1.34 m/s) Feedback is provided instantly The amount of time it takes to react to stimuli by clenching a

fist is equal to the time it takes to react by changing course. The amount of time required for the brain to receive feedback

from tactile stimuli at the hand and shoulder are the same.Equations Used: (sites.google.com/site/danielassupercoolbiologylab/)

Results:

Conclusion:The minimum distance between the user and an obstruction before the cane initiates haptic feedback is 0.28 m. Additional space is to account for cane delay.**Values calculated are worst-case minimum values. Additional space is necessary for practical use.



How does user height affect sensor height?Background: Most typical canes are sold in varying lengths.Assumptions: Sensor is in the middle of the cane Cane length: 52” (middle value) Height of armpit for 5’ and 6’ person is 47” and 56”,

respectively. Arm length for 5’ and 6’ person is 19” and 26”, respectively.Equations Used:

Results: H5 = 17.4”=Sensor Height for 5’ person H6 = 18.7”=Sensor Height for 6’ personTherefore the sensor for the 5’ person will only be 1.3” lower than the sensor for the 6’ person. It was expected the sensor for the 6’ person would be significantly higher, but their extra arm length helps keep the sensor lower. Conclusion:For future sale of the cane varying cane lengths should be considered, but the height of the sensors on the cane prototype should be fairly similar.



Will the additional weight of the cane have a significant negative impact on the user?


𝜃𝑚𝑔

• Additional weight is centered• Height (bottom of foot to top

of head): H=2m• ∆m=.454kg• =45 degrees

What does this mean?

Feasibility Analysis: Question 6 How much is the user effected if the sensors are

placed at the bottom, compared to them being placed near the top. Assumptions:

Center of gravity is where the cane is held/handle. It is being held at a 45degree angle at all times. Average weight of cane handle: 3 lbs Average weight of sensors: .25 lb

Equations: Center of mass of regular cane: 0.5ft Center of mass with sensors near handle: 1ft Center of mass with sensors near tip: 2.75ft


Updated Engineering Requirements

Rqmt. #Importanc

eSourc

eFunction Engr. Requirement (metric)

Unit of Measur

e

Marginal

Value

Ideal Value

S1 9 CR1System

Operation Provide 90 degree detection range in front of userDegree

s 90

S2 9 CR1System

OperationSignal detection of obstacles via haptic feedback (horizontal and vertical motion in handle) Binary

S3 3 CR2System

Portability Adds no more than 1 lb. to standard white cane Lbs. 1

S4 3 CR3System

AssemblyDecrease number of existing parts by ~50% or more Pieces

S5 3CR4, CR5

System Operation 8 hour rechargeable battery (minimum battery life) Hours 8

S6 3 CR6System

Portability Collapsible into 8-10" sections Inches 10 8S7 3 CR7 System Cost Manufacturing cost $125 or less USD 125

S8 1 CR8System

AssemblyDesign assembly process to be completed in a blind assembly environment Binary

S9 3 CR9System Usability Keep cane collapse/re-open time less than 1 minute Minutes 1

S10 9 CR10System

Operation Horizontal detection range Feet 6 10

S11 9 PRP N/A Prototype cost USD 1000<100

0

S12 3 CR12System

Operation Maximum pressure psi 3 5

S13 3 CR10System

OperationTime from motor input signal to when the roller reaches the minimum rotation speed at 3 psi Grip ms 500 <400

S14 3 CR11 System SafetyCircuit voltage V 12 <12

S15 3 CR12System

Structure Handle contents fit within handle mock up envelope Binary Pass Pass

S16 9 CR12System

Structure Maximum handle grip diameter in 1.5 0.78Importance: Sample scale (9=must have, 3=nice to have, 1=preference only), or see Ulrich exhibit 4-8.


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Documents

MSD I SMART CANE INTEGRATION SYSTEM SYSTEMS DESIGN PHASE REVIEW P15043 October 2, 2014