The Smart Walker
Project
TEAM: CHEN ZHANG, YI LU
PRESENTED BY: YI LU
Background
3 million walker users in America
2/3 report limitations in instrumental activities of
daily living
1/3 still need assistance from others
Customer Need and Project Scope

Standing-up support

Gait assistance through acceleration detection

At least 2-3 hours of sustain

Portable
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
Outline of the Frame
Schedule 40 6063 T6 Aluminum pipe
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
Pressure Analysis
Walker weight limit: 1.34kN (300lb)
Force on each pipe = 0.68kN/2=0.34kN
Surface Area:
𝜋 0.02672 − 0.02092 𝑚2 = 8.67 ∗ 10−4 𝑚2
Maximum pressure:
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
Tilt Analysis
Take D as the pivot point.
The force exerted on the frame has an angle α from the
vertical position.
𝐹𝑣
𝑀ccw
𝐹ℎ
𝑀cw (contributing factor for tilting)
As long as 𝑀ccw ˃𝑀cw , the frame will not tilt
α =12.9 °
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
Tilt Analysis (cont’d)
Take A as the pivot point
𝐹𝐶ℎ
𝑀ccw (contributing component for tilting)
𝐹𝐷
𝑀cw
As long as 𝑀c𝑤 ˃𝑀𝑐𝑐𝑤 , the frame will not tilt.
α =34.1 °
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
The Electronic Sensor System
The Processor
•The Arduino UNO
•Robust
•8-bit microcontroller
•14 digital pins and 6 analog pins
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
The Accelerometer for Gait Assistance
ADXL345
Measurement range: ±2, ±4, ±8, ±16 g
Resolution: 3.9mg/LSB (10bits)
Acceleration: 0.52g
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
The Accelerometer for Gait Assistance
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
The Ultrasonic Range Finder
HC-SR04 Ultrasonic distance measuring sensor
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
Mechanism
Sensor 1 : Upper body distance from the frame.
Sensor 2: Lower body distance from the frame.
Need and
Scope
Feasibility
Chose Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
Performance Calculation
Maximum sensing range: 2m
Two sensors attached to the midpoints of pipes
To make sure that the sensors work when the
object appears 2m to the edge of the frame:
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion and
Next Steps
The Frame
55.9cm×45.7cm×99.1cm
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next Steps
Flow Chart: Standing-up Support
Need and Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion and
Next Steps
Flow Chart: Gait Assistance
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next
Steps
Wiring Diagram and Power Calculations
The Arduino pins draws most of the power
9V DC battery
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next
Steps
Parts and Costs - Frame
Price of the frame: $180
Weight of the frame: 5kg
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next
Steps
Parts and Costs - Electronics
Price of the electric system: $155
Weight of the electric system: 1.07kg
Total price: $335
Total weight: 6.07kg
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next
Steps
Assembly
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next
Steps
Electronics Mounting
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next
Steps
Conclusion and Next Steps
Basic functions achieved
Still needs to improve on functionalities




Motor and hydraulic brake combination
Gradual speed reduction
User profile memory
Foldability
Need and
Scope
Feasibility
Chosen Design
Details
Parts and
Manufacturing
Conclusion
and Next
Steps