Ankle Positioning Device

Spring 2013

Marc DeAngelisPaul HaurisKatherine LeshkowJennifer Moore

Complex Joint Full Range of Motion

Inversion/Eversion Plantar Flexion/Dorsiflexion Internal/External Rotaton

Background

IntroductionBasic Goals

x-, y-, z-axes

Load applied

Horizontal, vertical

5DOF

Our Goals

Working Model

User-friendly

Cost Effective

Minimal Machining

Pin• Layered• Framed

Plates• Gimbal

Pin

Designs

• 4DOF

Framed Plate

Layered

• 3 DOF

• 3DOF

• 4 DOF• Built upon

earlier ideas

Gimbal

Basic Conceptual Design • Selected Design• 4 DOF

Clamp Design (Tibia)

Design Modifications• Joint Design• Motors• Load Cell

Joint Design

• Calculations• Torque Consideration• Weight Requirement• Final Selection

100 lbs

Design Modifications - Motor Selection

Design Modifications - Load Cell• Function• Importance of Location

• Necessary Change• Earlier Design’s Flaws

Design Flaws - Structural Support

Design Flaws – Translational Flaw

Control Algorithm

Control Algorithm

Servo without Filter

Servo with 2nd Order Butterworth Pass Filter

Cost Analysis• Base Plates

• 24” x 24” 1” thick Al plate - $544.97• 18” x 18” 1” thick Al plate - $306.55

• Stabilizer Base

• 3/16” thick Al - $63.19

• Three Motors - $719.94

• Vertical Bearings - $92.88

• 6DOF Analog IMU - $72.50

• Arduino Uno - $29.95

• TOTAL ESTIMATED COST: $2,768

Gantt