System Design ReviewSmart Walker

Project Description • Project Background• Problem Statement• Scope• Deliverables

Work Breakdown

Navigation

Fall Detection

Monitoring User

Collect Vitals

Room Layout

Customer NeedsP13041 Customer Needs

Customer Need # Importance Description Comments/Status

CN1 1 Functionally unobstrusive to the user CN2 1 Functionally autonomous but independent of locating the user (avoid obstacles) CN3 1 Locate user when in trouble using microphone array independent of autonomy

CN4 1 Support user's weight

CN5 1 Collect heart rate

CN6 1 Collect temperature

CN7 1 Collect weight fluctuation of the patientSensor under seat (not full weight accounted for when sitting)

CN8 1 Feedback to a local hub be wireless

CN9 1 Measure tendencies of how much user relies on walker for stability(fall "saves", distance traveled, velocity,accel)

CN10 1 Meet budget

CN11 1 Must meet battery life requirements

CN12 1 Allow for ability for live feed data during autonomous navigation

CN13 1 Monitoring systems need to not be visible to the user (aesthetically pleasing)

CN14 1 Needs to be programmable and have a user interface (for doctor) max/min vitals

CN15 1 Detection of the user falling down

CN16 2 Collect Body Fat (BMI) Fluctuation

CN17 3 Detect smoke in the environment

CN18 3 Capable of stability control

CN19 3 Alert user if obstacle in path of motion

Revision #3Importance: Sample scale (1=must have, 2=nice to have, 3=preference only), or see Ulrich exhibit 4-8.

Specifications Spec. # Importance Source Function Specification (metric) Unit of

MeasureMarginal

ValueIdeal Value Comments/Status

S1 CN1 Noise should not exceed Decibels S2 CN1 Walker height cm 96 S3 CN1 Walker width cm 62 S4 CN1 Walker depth cm 70 S5 CN1 Walker weight kg 25 20 Stock 8.2S6 CN2 Time to Successfully Navigate to user min 60 5 S7 CN10 Meet Budget dollars 2,000 8,000 S8 CN2 Use SLAM boolean 1 S9 CN2 Minimum distance to detect obstacle cm 10

S10 CN3 Minimum distance from user when locating with navigation cm

S11 CN3 Audibly detect fall within a range m

S12 CN5 Detect heart rate within (Time) s

Need to determine how many beats are required

to detectS13 CN5 Detect heart rate periodically s S14 CN6 Temperature accuracy °F S15 CN6 Distance to measure temperature m S18 CN4 Weight capacity kg 91 S19 CN11 Battery life in passive mode days 1 2 S20 CN11 Battery in active mode minutes 60 S21 CN8 Non-emergency updates to local hub hours 24 S22 CN8 Emergency update to local hub s 5

S23 CN8 Send all last recorded vitals to local hub with in (?sec) of entering emergency mode s

S24 CN6 Detect temp within (Time) s S25 CN7 Detect weight within (Time) s S26 CN16 Detect BMI within (Time) s S27 CN7 Weight Accuracy kg

System Design Schematic

Software Flow Chart

Signal Processing

Concept Selection: Walker

CS: Obstacle detection

CS: Drive

Odometry

CS:

CS: User Weight

CS: Wireless Communication

CS: Heart Rate Monitoring

CS: BMI

CS: Temperature

Project Plan

Risks

ID Risk Item Effect Cause

Likelihood

Severit

y

Importanc

e

Action to Minimize Risk Owner

1

Customer fails to deliver promised algorithms

Walker will not function seamlessly. Must develop additional testing procedures to prove sub systems work.

Will take significant time to prove sub systems 2 1 2

Reduce: Under stand what Algorithms are expect to be put in place early

2Battery is too small to meet specs

Fail to meet, S20&21 (battery life)

Motor takes more power than predicted, overall weight is heavier, computer draw is high, wifi draw is high

2 2 4Prevent: Use a battery that is overkill and can later be sized down.

3

Unable to detect heart rate when walking via camera

Fail to meet CN5 & S13Currently available technology is not able to work without stationary person.

2 2 4

Transfer: Have customer understand that we will put camera in place for use but it is not our job to insure it works in motion

4Programming will not be begun in time

A working model will be delayed. Won't meet delivery date

2 2 4Reduce: Ensure that other deliverables are met on schedule

5Microcontroller is not sufficient

We essentially have to start from scratch

Insufficient knowledge of how to select a microcontroller to meet our needs

1 3 3

Reduce: Attend "Which Micro" lecture on Friday 12/21/12 Prevent: Over-compensate computing needs.

Risks Con’t

6Parts that are spec'd will be unavailable

Parts with different spec's will delay development of PCB or not be compatible with PCB

Rare/ extremely specialized parts 2 3 6

Reduce: Spec common parts, Check to see if in stock before adding to BOM, Order Early (week 10)

Team

7Unable to develop a BMI technology for walker use

Walker will not be able to detect BMI

Under estimating the complexity of the BMI handheld unit

3 1 3 Accept: We will not have BMI on the walker James

8

Unable to develop a temperature monitoring technology for walker use

Walker will not be able to detect temperature

Under estimating the complexity of the Temp Gun 2 2 4

Reduce: Look into temp gun tech early and find another solution if not possible

Rika

9

A failure during testing causes destruction of another subsystem

Walker will be broken, Will have to be rebuilt, could fail to have deliverable in May

Poor designing 1 3 3Reduce: Design testing procedures so that possible destructive testing is last.

Team

10PCB is not designed or fabricated in time

Electronics and wiring of all sensors will be set back. Programming will also be delayed.

Poor time management or unexpected issues with fabrication/board itself

2 3 6

Reduce: Design carefully in order to prevent any extra emf signals or other common PCB issues. Also, design early and possibly have the design checked by peers/mentors.

EE's