1. Air Muscle Artificial Limb
Project #: P08023
Air Muscle Artificial Limb
Jonathan Kasper / Project Manager Matthew Lewis / Design Lead Mark McKann / Controls Team
Jenna Fike / Lead Engineer Josa Hanzlik / Air Muscle Team Nick Rappa / Controls Team
Dr. Kathleen Lamkin-Kennard / Advisor Ellen Cretekos / Air Muscle Team Eric Giang / Controls Team
Abstract
The primary goal of the Air Muscle Artificial Limb project is to design, build, and control a robotic hand with realistic finger motions; all gesticulations are made possible via forces produced by pneumatic muscles. Dr. Kathleen Lamkin-Kennard, of the Bio-Mechanical Engineering Dept. at RIT, facilitated the project with specific product requirements and team guidance. In order to achieve the project objective, a team of engineers was divided into Design/Build, Air Muscles and Controls sub-teams. During the initial stage of the project, three fingers were prototyped, control algorithms were created, and air muscles were characterized in order to produce a consistently and accurately controlled hand. The final product is an aluminum hand with index, middle, and ring phalanges that are capable of achieving four degrees of freedom (DOF): flexion, extension, abduction, and adduction.
Project Overview
Potentiometer
DAQ
Feedback
LabVIEW
Relay Board
Portable Air Compressor
Valves
Air Muscles
Finger CAD Design
Artificial Limb CAD Design
System Architecture
Controls Team : in charge of implementing control mechanisms
and algorithms for management of the solenoid valves that were
used to manipulate air flow
Design/Build Team : responsible for configuring and producing a robotic hand that was capable of the requisite hand motions; this included the production of:
CAD drawings
Prototypes
Final functioning hand.
Read configuration file to determine relative potentiometer range
= Ab/Adduction Instruction
= n% Flexion Instruction
= Too Flexed
= Too Extended
= Absolute Direction
Air Muscle Team : focused on the development and implementation of air muscles for the project.
Wait for User’s Command
Determined the method for constructing reproducible muscles
Evaluated optimal sizes and materials
Characterized the bladders so that they were capable of consistently producing the necessary forces
Call AB/AD module
Determine current % flexion
Push-to-connect
Eye-Hook
Finger Abducts or Adducts
Cycle extension valve once
Cycle flexion valve once
Inside Tubing: Rubber
Finger Flexes by Instructed Percentage
Mesh Material: PET
Air Muscle Displacement Based on Pressure and Length
Logic Diagram of Finger Actuation Control
Results/Conclusion
Future Work
3 Fingers capable of the 4 DOF: Flexion/Extension & Abduction/Adduction
Control Feedback obtained via Linear Potentiometers
Forces produced by 9 Air Muscles with the following lengths:
[3] Abduction & [3] Adduction – 2.5 in
[2] Flexion (Index and Ring Fingers) – 7 in
[1] Flexion (Middle Fingers) – 6 in
Ease of air muscle serviceability
Addition of pinky, thumb, and wrist motion
Grasping capabilities and tactile feedback
Simultaneous flexion of varying degrees
Air muscles with increased life expectancy
Improvements in maintenance and assembly
Final Limb
Acknowledgements
Special thanks to Dr. Kathleen Lamkin-Kennard, Mr. John Wellin, Mr. Scott Kennard, Dr. Steven Day, Dr. Matthew Marshall, Mr. William Scarbrough, Mr. Edward Hanzlik, Mr. David Hathaway, Dr. Mark Kempski, Mr. Robert Kraynik, and Mr. Jonathan Niebielski