Final Design Team # 17 Michael Bunne, John Jagusztyn, and Jonathan Lenoff Department of Mechanical Engineering, Florida State University, Tallahassee, FL Project Sponsor: Project Advisors: Dr. Emmanuel G. Collins, Ph.D Department of Mechanical Engineering Dr. Oscar Chuy, Ph.D Department of Mechanical Engineering

Introduction 1 of 24 Problem Statement The current generation of assistive walking devices is limited in their traversable terrain and functionality. Indoor operation only Only perform basic functions Scooters / electric wheelchairs unnecessary or expensive Proposed Solution Develop a walking assistive device designed to actively assist the user in both indoor and outdoor maneuverability. Further empower the disabled and elderly community Offer wide-range of assistive functions Maintain ease of use and intuitiveness integral to current generation walkers

Criteria Versatility Robustness User-friendliness Indoor operation Outdoor operation Cost Weight Specifications Frame Resemble current generation walker in aesthetics and standards 1 inch square aluminum framing Supports up to 300 pounds Adjustable heights between 32 and 39 inches Adjustable handle width between 11 and 24 inches Propulsion Minimum 11 inch diameter wheels or tracks Travel over all indoor surfaces, grass, gravel… Travel up or down slopes up to 10 ° Move transversely 45° from the center axis Maximum operating speed of 5 mph Control & Function Intuitive user input Force-based drive control Fall Prevention Sit-Down/Stand-Up Assistance Object Detection/Avoidance Localization & Navigation 2 of 24

Concept 1 Design 1)Driving Wheel 2)Driving Motor 3)Encoder 4)Elbow Couple 5)Adjustable Spring 6)Damper 7)Spring Housing 8)Elbow Couple 9)Ackerman Steering 1)Driving Wheel 2)Driving Motor 3)Motor Encoder 4)Spring & Damper 5)Ackerman Steering 6)Steering Motor 7)Caster Wheel 8)Caster Suspension & Swivel 9)Basket / Electronics 10)Force Plate 11)Camera 3 of 24

1)Honeycomb Wheel 2)Elbow Gearbox 3)Driving Motor 4)Encoder 5)Rotary Connection 6)Steering Motor 7)Spring 8)Damper 9)Controls Base 10)Spring Driven Controls 11)Basket / Electronics 12)Camera 13)Swivel and Suspension 14)Caster Wheel Concept 2 Design 1)Honeycomb Wheel 2)Elbow Gearbox 3)Driving Motor 4)Encoder 5)Rotary Connection 6)Steering Motor 7)Spring 8)Damper 9)Spring Housing 4 of 24

1)Grip 2)Damper 3)Spring 4)Depth Adjustment Shaft 5)Adjustment Shell 6)Mount / Width Adjustment Shaft 5 of 24 Spring Driven Controls

Concept 3 Design 1)Caster Wheel 2)Caster Suspension / Shaft Swivel 3)Motor Encoder 4)Driving Motor 5)Spring Elbow Couple 6)Spring 7)Spring Housing 8)Ackerman Steering 9)Basket / Electronics 10)Steering Motor 11)Spring Driven Handle 12)Laser Sensor 13)Spring Dampers 14)Frame 6 of 24

Concept 4 Design 1)Caster Wheel 2)Driving Motor 3)Rotary Connections 4)Steering Motor 5)Spring 6)Damper 7)Spring Housing 8)Laser Sensors 9)Force Plate Driven Handle 10)Driving Wheel 11)Caster Suspension 12)Motor Encoders 13)Basket / Electronics 14)Laser Sensor 7 of 24

Concept 5 Design 1)Driving Wheel 2)Driving Motor 3)Track Suspension and Tension Wheel 4)All-terrain tracks 5)Suspension 6)Front storage 7)Basket / Electronics 8)Spring Input 9)Foldable Seat 8 of

Criteria Versatility (15%) Robustness (17.5%) User-friendliness (22%) Indoor operation (14.5%) Outdoor operation (23.5%) Cost (4%) Weight (3.5%) Decision Matrix 9 of 24 Concept 1Concept 2Concept 3Concept 4Concept 5 WeightScoreWeightedScoreWeightedScoreWeightedScoreWeightedScoreWeighted Versatility Robustness User-friendliness Cost Indoor Outdoor Weight Sum:

Interim Design Analysis Based on preliminary investigation, further detailed analysis was applied for: -Concept 1 -Concept 2 -Concept 5 Analyzed for: -Locomotion -Steering -Controls 10 of

Air Filled TireHoneycomb TireTreads Average Life25,000+ Miles 75,000+ Miles TractionAverage Very High Outdoor Operation Average (High potential for slip, small footprint) Average (High potential for slip, small footprint) High (Large footprint) Indoor Operation High (Small footprint) High (Small Footprint) Low (Large footprint) Puncture ResistanceMildly ResistantHighly Resistant Environment Conditions Mud, Ice and Snow present potential issues All Conditions Possible Failures Exploding Tires (Over pressurized), tears or leaks that let out air Chunks can be removed from tire Cracked Tiles, chain or driving belt may come off Possible RepairsLeak Stop, Foam Filling Rubber like material to fill in gashes Replace Individual Tiles Suspension AssistanceAverageHighNone Obstacle TraversibilityLowAverageVery High Overall ComplexityLow High Locomotion 11 of 24

Ackerman SteeringIndividual Steering MotorsSkid Steer Necessity for additional support electronics LowHighLow Size of Additional Motor Necessary Large (Must steer both wheels) Small (Load is split amongst motors) None (Driving motors steer) Capability for Use Unpowered/Broken High Very Low Turning Radius~5 ft min00 Holographic MovementNoYesNo “Module” CompatibilityNoYes Possible Failures Joints or joining bar may deform or break Rotary Connection may fail Chain or driving belt may come off Overall ComplexityAverageHighLow Steering 12 of 24

Force PlateSpring Driven Controls Max Input Force~5 Pounds~500 Pounds Part Replacement/RepairExpensive and DifficultCost Effective and Easy Moving PartsNoYes Possible FailuresSolid State electronics may be damagedPotentiometers may break, springs may deform Environment ConditionsWater must be kept away from force plateAll Weather Number of Input Axes62 Overall ComplexityHighLow CostHigh (~$5,000)Low (~$100) Controls 13 of 24

Design Synthesis Based on our further investigation, aspects of each of the designs were combined to form a Final Design Concept: 14 of 24

Final Product Design 1.0 Components: 1)6 Wheels -2 Driving, 4 Passive Casters 2)All Individual Steering 3)New Wheel Design 4)Modular Wheel Attachment 15 of 24 (old) (new)

Final Product Design of in 30 in 33in

Fixes: 1)Swivel Casters 2)Angled Caster Mechanisms 3)Smaller User Restriction Problems: 1)“In Line” Passive Casters 2)No horizontal shock absorption 3)Too constricting to user Final Product Design of 24 Final Product Design 1.0

Final Product Design of 24

Spring Selection 19 of 24

Motor Selection 20 of 24 (wheel)

Health & Safety 21 of 24 Human Health & Safety: -Stand-Up Assistance -Fall Prevention -Object Avoidance -Control Calibration/Regulation Environmental Health & Safety: -Electric Motors -Permanent Basket -Low Risk Materials

Motors Wheels Stock Hardware Electronics Overall Cost Estimation 22 of 24 MotorsEstimateQuantityTotal Driving$1002$200 Steering$5002$1,000 Wheels Driving$502$100 Caster$404$160 Stock Hardware$3001 Electronics Computer$0Donated$0 Power Supply$0Donated$0 Battery$502$100 Encoders$752$150 Overall:$2,010

Future Work 23 of 24 Future work can be broken down into the following sections: -Part Ordering -Part Receiving -Manufacturing -Assembly -Testing/Redesign -Final Assembly Further Analysis will be conducted for: -Center of Mass -Payload Capacity -Control Schemes

Timeline 24 of 24

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Dr. Oscar Chuy Dr. Emmanuel G. Collins CISCOR Dr. Rob Hovsapian Dr. Srinivas Kosaraju Dr. Chiang Shih Gerald Tyberghein Questions? Thank you