Team Robotic Hand Mechanics

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Team Robotic Hand Mechanics
www.shadowrobot.com/gallery.shtml?galleryhandCim
gHandC_CRW_9344.jpg
Evan Coombs (evan_coombs_at_hotmail.com) Bryan Adams
(bsasdams_at_yahoo.com) Robert Poulsen
(robbiepoulsen_at_msn.com) Tyson Skinner
(teskinut_at_hotmail.com)
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Overview

• Current Products
• Previous Design Teams Work
• Prototype
• Transmission
• Finger
• Budget
• Schedule

12/07/2006 Team Robot Hand Mechanical
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Current Products

• Existing Hand Designs
• SMA Actuation
• Motor Controlled Hands
• Air Muscle Actuated Hands
• Anthropomorphic Design

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Current Products
SMA Wire

• Shape Memory Alloy (SMA)
• Products available
• Wires
• Springs
• Pistons
• Actuation Types
• Electrical Current
• Water
• Any Temperature Changing Media

http//www.smelectronics.us/microwavecablesman.htm
SMA Spring
http//www.robotstore.com/store/product.asp?pid85
catid1570
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Current ProductsSMA Actuated Pantograph Robot
Overall View Pantograph Robot
Front View SMA wire Attachment
SMA Wire
http//users.rsise.anu.edu.au/roy/SMA/pantograph/
panto_front.html

• Actuation by Electric Current
• Fast Actuation - 1Hz

http//users.rsise.anu.edu.au/roy/SMA/pantograph/
panto_big.html
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Current ProductsSMA Actuated Spring Piston
SMA Spring Piston

• Electric Current Actuation

www.robotstore.com/download/EPiston_Instr_V12.pdf
, page 2, Figure 1
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Current Products The Southampton Hand
The Southampton Hand

• Anthropomorphic
• Uses tactile feed back
• Electric Motor actuation

www.ecs.soton.ac.uk/phc/The_Southampton_Remedi_Ha
nd.jpg
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Current Products
Pneumatic Actuation
Under-Actuated Design Deformation to Allow Grip
wwwrobot.gmc.ulaval.ca/recherche/theme04_a/Closing
Sequence.jpg.html

• Pneumatic Actuation
• Extensive Gripping Potential

wwwrobot.gmc.ulaval.ca/recherche/theme04_a/ mainpn
eumatique.jpg.html
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Current Products The Shadow Hand
Shadow Hand

• Pneumatic Actuation
• Anthropomorphic
• 24 degrees of freedom

www.shadowrobot.com/gallery.shtml?galleryhandCim
gHandC_CRW_9331.jpg
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Current Products Anthropomorphic Design
Hollow Bone Model of Finger
www.ai.mit.edu/projects/humanoid-robotics-group/Ab
stracts2000/banks.pdfsearch 22shape20memory20
alloy202B20finger22
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Previous Teams Contributions

• Finger
• Transmission
• Actuation

Actuation Block
Transmission
Finger Assembly
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Previous Years Finger

• U-channel links
• No extension capability
• Unpredictable tendon connections

Larger U channels
Last Years Finger Design
Tendon connections
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Previous Years Transmission

• Poor functionality
• High friction pulley system
• Bulky design
• Too complex

Bulky chain-link components
High friction pulleys
Last Years Transmission Design
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Previous Years Actuation

• Poor seal
• Too small to incorporate all functions

4x4 Array block
Leaky connections
Last Years Actuator Design
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Whats cool about the project

• Our design will have a controlled flexion and
  extension
• Will have multiple fingers
• Will be more anthropomorphic

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Prototype Goals

• Prototype Components
• Transmission
• Finger Assembly
• Reason For Choice
• Essential for Construction
• Major Problems for Previous Design Team
• What Can Be Learned
• Determine Design Feasibility
• Determine if Design Goals Can Be Met

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Prototype-Transmission
Solid Model Transmission Design

• Components
• Shape Memory Alloy (SMA) Springs
• End Plug
• Silicone Boot

Team Robotic Hand Mechanics 2007
Transmission CFP
Silicone Boot
Internal SMA Springs
Water Flow Port
End plug
Team Robotic Hand Mechanics 2007
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Transmission Function
Fully Extended
ADD HOT WATER
Fully Contracted
Force2.2 lbs
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Prototype-Transmission

• SMA Springs
• Pros
• Reduced Size
• High Displacement
• 20 mm
• Lower Actuation Temperature
• Minimized Friction
• Cons
• High Cost
• Low Strength
• 3.4 N

SMA Spring
http//www.robotstore.com/store/product.asp?pid85
catid1570
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Prototype-Transmission
Solid Model End Plug Design

• End Plug
• Pros
• Reduced Size
• Easily Modified
• Cheap
• Reduces Chance of Fluid Loss
• Cons
• Not a COTS part
• 90 min. Machine Time

Actuator Attachment Point
Water Flow Port
SMA Spring Attachment Point
Water Flow Port
Team Robotic Hand Mechanics 2007
Actuator Attachment Point
Machined End Plug
SMA Spring Attachment Point
Water Flow Port
Team Robotic Hand Mechanics 2007
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CFP-Transmission
Silicone Boot Solid Model

• Silicone Boot
• Pros
• Reduced Friction
• Displacement Similar to SMA Springs
• Small Force Required to Induce Flexion and
  Extension
• Cons
• Not a COTS Parts
• Difficult to Manufacture

Team Robotic Hand Mechanics 2007
Partial Silicone Boot
Team Robotic Hand Mechanics 2007
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Prototype-Transmission
Split Mold

• Silicone Boot Mold
• Pros
• Custom Design
• Easy to Make Multiple Boots
• Easily Altered Design
• Inexpensive
• Cons
• Intensive Initial Construction
• Equipment Setup and Adjustment (10 Hours)
• Software Setup and Debugging (15 Hours)
• Core Pin (1 Hours)
• Outer Mold (2 Hours)
• Centering Block (1 Hours)
• Insufficient Silicone Flow in Mold

Team Robotic Hand Mechanics 2007
Fully Assembled Mold
Team Robotic Hand Mechanics 2007
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Prototype-Finger
Cross-Sectional View of Proposed Finger Design
Reverse Bias Cams

• Pros
• Flexion and Extension
• Low Friction
• Light Weight
• Anthropomorphic Design
• Precision
• Reverse Biasing
• Tendon Attachment
• Cons
• Cams Need Refinement
• Machinability of Material
• Tendon Routing

Finger structures
Tendons
Stand
Team Robotic Hand Mechanics 2007
Finger CFP
Finger structures
Reverse Bias Cam
Stand
Team Robotic Hand Mechanics 2007
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Cost

• RobotStore.com
• SMA Springs 41.95
• Cabelas
• Kevlar Thread (tendon) 3.99
• McMaster-Carr
• Set Screws 9.96
• Dowel Pins 8.40
• Bearings 27.60
• Stand Mat. 11.49
• Finger Mat. 13.88
• Sleeve Mat. Donated
• Aluminum Stock Donated
• CNC Machine Time Donated
• Total 117.27
• Budget Left 82.73

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Schedule

• Future Accomplishments
• Refine CFP
• Spring Strength 12/8/06
• Actuator Design 3/1/07
• Cam Design 3/1/07
• Wire Routing 4/1/07
• Complete Palm Design 4/1/07
• Implement Finger into Whole Hand 4/27/07

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Summary

• Current Products
• SMA Wire Actuation
• Electric Motor and Air Actuation
• Previous Design Teams Work
• Prototype
• Transmission
• Finger
• Cost
• Only spent about 120.00
• Schedule
• On Schedule
• 4 Fingers Assembled to Palm by April 2007

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Questions?

• Team Members
• Evan Coombs evan_coombs_at_hotmail.com
• Bryan Adams bsasdams_at_yahoo.com
• Robert Poulsen robbiepoulsen_at_msn.com
• Tyson Skinner teskinut_at_hotmail.com
• Project Advisor
• Dr. Stephen Mascaro smascaro_at_mech.utah.edu

12/07/2006 Team Robot Hand Mechanical