Open-Aid
description
Transcript of Open-Aid
12/7/2004 AME470 Ltd. - Team Pratham 1
Open-AidOpen-Aid
TEAM PRATHAMTEAM PRATHAMTeam Leader: Matt RyanTeam Leader: Matt Ryan
Chief Engineer: Nick MartinChief Engineer: Nick MartinFabrication: Reed LangtonFabrication: Reed Langton
CADCAM: Fraterno VilaCADCAM: Fraterno VilaElectronics/Control Engineer: Electronics/Control Engineer:
Gabriel LetonaGabriel Letona
12/7/2004 2AME470 Ltd. - Team Pratham
OutlineOutline Problem DefinitionProblem Definition Product RequirementsProduct Requirements OperationOperation Prototype Prototype Design IssuesDesign Issues Strengths and WeaknessesStrengths and Weaknesses Budget SummaryBudget Summary
12/7/2004 3AME470 Ltd. - Team Pratham
Problem DefinitionProblem Definition
Break the seal on jars and bottles Break the seal on jars and bottles without requiring the user to apply the without requiring the user to apply the torque necessary to open themtorque necessary to open them
12/7/2004 4AME470 Ltd. - Team Pratham
Product RequirementsProduct Requirements
Container Specifications
Twist off cap/lid
Total Height 2 - 10 in.
Body Diameter 1.5 - 5 in.
Lid Height 0.3 - 1.0 in.
Lid Diameter 1 - 5 in.
12/7/2004 5AME470 Ltd. - Team Pratham
Open-AidOpen-Aid
Ability to open a glass or plastic Ability to open a glass or plastic containercontainer
Uses a microprocessor with Uses a microprocessor with feedback from sensors to control the feedback from sensors to control the driving motorsdriving motors
12/7/2004 6AME470 Ltd. - Team Pratham
Prototype vs. ConceptPrototype vs. Concept• Housing - Box vs. Cylinder
• Height Adjustment
• Fabricated bottom half
12/7/2004 7AME470 Ltd. - Team Pratham
OperationOperation
12/7/2004 8AME470 Ltd. - Team Pratham
Programming (Opening Programming (Opening Container)Container)
Yes
No
Stop bottom assembly motor
Does Hall effect sensor 1 still sense
magnet?
Hall effect sensor 2 senses magnet
Count to 1
second
Stop turning top assembly motor
Start turning bottom assembly motor
Sense top assembly
contact switch
Has bottom assembly contact
switch been pressed?
No
Turn top assembly motor
on
Plug in
appliance
Press ‘start’ button
Yes
Stop bottom assembly motor and
go to release operation
12/7/2004 9AME470 Ltd. - Team Pratham
Programming (Releasing Programming (Releasing Container)Container)Reverse top assembly motor
Sense top assembly hall effect sensor
Stop top assembly motor
Reverse bottom assembly motor
Hall effect sensor 1 senses magnet
Stop bottom assembly motor
12/7/2004 10AME470 Ltd. - Team Pratham
The PrototypeThe Prototype
12/7/2004 11AME470 Ltd. - Team Pratham
The PrototypeThe Prototype• Sensors - Contact switches moved to breadboard
Prototype
Concept
12/7/2004 12AME470 Ltd. - Team Pratham
Design IssuesDesign Issues
Torque Requirements Torque Requirements Motor SelectionMotor Selection Plate DesignPlate Design Gripping ComponentsGripping Components ElectronicsElectronics
12/7/2004 13AME470 Ltd. - Team Pratham
Torque RequirementsTorque RequirementsREQUIRED TORQUE EXPERIMENTAL DATA
Container Weight Force Lever Arm Torque Torque
(kg) (N) (m) (N-m) (oz-in)
Glass Applesauce Jar** 1.275 12.51 0.26 3.25 460.52
Glass Salsa Jar 3 29.43 0.243 7.15 1012.72
Plastic Powerade Bottle 0.75 7.36 0.262 1.93 272.98
Glass Snapple Bottle 1.2 11.77 0.253 2.98 421.76
**For this first experiment, the jar was laid horizontal. The equivalent mass of the lever arm is factored into the weight shown here
12/7/2004 14AME470 Ltd. - Team Pratham
Motor SelectionMotor Selection
Buehler 12V DC Gearmotor w/ 6:1 Gear Train
Output Power 0.015 hp
Torque 1944 oz-in
Angular Velocity 6.25 rpm
Weight 1.5 lbs
Diameter 1.2 inches
Length 3.3 inches
Shaft Length 0.4 inches
Motor Selection:
12/7/2004 15AME470 Ltd. - Team Pratham
Gear TrainGear Train
6:1 gear ratio 6:1 gear ratio required to transmit required to transmit operating torque with operating torque with the Buehler DC motorthe Buehler DC motor
Stainless steel clamp Stainless steel clamp hub gears from Berghub gears from Berg
Clamps secure gear Clamps secure gear and pinionand pinion
12/7/2004 16AME470 Ltd. - Team Pratham
Plate DesignPlate Design
Resulting Force on Grips from Spiral Groove
Grip rests at intersection of linear and spiral grooves
Motor output results in the spinning of the Plate w/ Spiral Grooves, causing the Grip to move towards the center of the plates along the linear groove
Grip
Plate w/ Linear Grooves
Plate w/ Spiral Grooves
Linear Groove
Spiral Groove
Convergence Angle
12/7/2004 17AME470 Ltd. - Team Pratham
Plate DesignPlate Design
Torque Key
Torque Key
Motor
Gears
• Torque Key is fastened to the central shaft with a spring pin
• Torque Key interlocks with Plate w/ Spiral Grooves
12/7/2004 18AME470 Ltd. - Team Pratham
Gripping ComponentsGripping Components
Concept – three Concept – three gripping gripping components components consisting of a consisting of a gripping arm riding gripping arm riding in a slotted bracket, in a slotted bracket, with a spring and with a spring and contact switchcontact switch
Inserts into spiral Inserts into spiral and radial platesand radial plates
Spiral
Radial
12/7/2004 19AME470 Ltd. - Team Pratham
Gripping ComponentsGripping Components Prototype – single unit with high-friction Prototype – single unit with high-friction
synthetic polymer padssynthetic polymer pads Problem – prototype slips on glass containersProblem – prototype slips on glass containers
Radial Plate
Spiral Plate
12/7/2004 20AME470 Ltd. - Team Pratham
Electronic SchematicElectronic Schematic
12/7/2004 21AME470 Ltd. - Team Pratham
Microcontroller System Microcontroller System and and
Power SourcePower Source Minimax Minimax MicrocontrollerMicrocontroller Microprocessor Microprocessor
PIC16F877APIC16F877A Demands 6 to 12V DCDemands 6 to 12V DC 100mA minimum 100mA minimum
currentcurrent Provides 5VProvides 5V
External Power External Power SourceSource 120V AC from outlet120V AC from outlet Use of an AC-DC Use of an AC-DC
adapter power source adapter power source converterconverter
12/7/2004 22AME470 Ltd. - Team Pratham
SensorsSensors Magnetic Hall Effect sensors are used to control Magnetic Hall Effect sensors are used to control
the rotation of the plates during the opening of the rotation of the plates during the opening of the containerthe container
Magnet 1
Housing
Hall Effect Sensor
Container to Open
Lower Plate Assembly
12/7/2004 23AME470 Ltd. - Team Pratham
SensorsSensors
Contact Switches
Hall Effect Sensor & Magnet
12/7/2004 24AME470 Ltd. - Team Pratham
H-BridgeH-Bridge 2 NMIH-0030 H-bridges DC motor applications from 6 to 18 V up DC motor applications from 6 to 18 V up
to 5 A currentto 5 A current Provides forward, reverse, and brake
modes of operation.
12/7/2004 25AME470 Ltd. - Team Pratham
Strengths and Strengths and WeaknessesWeaknesses
Component Strength Weakness Importance
Spiral Plateunlimited number of
potential grippers; one motor per plate assembly
Carefully selected geometry
high - the basis of design for the entire product
Magnet Sensorsonly sensors require
power, magnet does not
Requires close proximity to moving
plates
medium - sense position of container; there are no wires
to tangle
Grippersspring loaded for more
uniform grasping
increases part count, only a fixed force reaches contact
switch
medium - ensures that all grippers grip with even force
Contact Switches Small wires can get twisted
if not controlled
medium - wires twist, which must be accounted for in the
design
Gearspositive contact/force
transmission
may be loud, small pitch requires
precision
high - gears transmit the torque to the container applied by the motors
Height adjustment
automatically moves up with lid displacement
requires user to initially adjust it
manually
low – automated system not necessary; user able to lift
top assembly manually
12/7/2004 26AME470 Ltd. - Team Pratham
Budget SummaryBudget Summary
Most expensive components:Most expensive components:
- Large Gear - Large Gear $43.00$43.00
- H-Bridge - H-Bridge $30.00 $30.00
Budget Available:Budget Available: $400.00$400.00 Total Budget used: Total Budget used: $338.00$338.00 Budget Left: $62.00Budget Left: $62.00