midterm ii
DESCRIPTION
Midterm II . Team 25: Oil Palm Harvester 11/12/13. Ricardo Aleman , ME Yuze (Liam) Liu, ME David Boswell , ECE Bolivar Lobo, IE. Review : Oil Palm Harvester. Goals Develop an effective, efficient, and economical oil palm harvester Tasks Study existing harvesting techniques - PowerPoint PPT PresentationTRANSCRIPT
Midterm II TEAM 25: OIL PALM HARVESTER
11/12/13
Ricardo Aleman , MEYuze (Liam) Liu, MEDavid Boswell , ECE
Bolivar Lobo, IE
2
Review:Oil Palm Harvester
• Goals • Develop an effective, efficient, and economical oil
palm harvester
• Tasks• Study existing harvesting techniques• Develop conceptual design• Carry out machine design• Create a product prototype• Report findings
• Midterm I presentation• Studied existing harvesting techniques• Presented 3 concepts• Selected cart
• Midterm II presentation• Develop conceptual design • Demonstrate mini prototype
RicardoRicardo
3
Review: Cart with Telescoping Pole and Cutting ToolCOMPONENTS
• Cutting Tool (A)
• Telescoping Pole (B)
• Cart (C)
• Power/ Auxiliary System (D)
Ricardo
A
B
C & D
Oil Palm
Palm Harvester
R ≤ 5ft
H ≤ 40ft
h = 4ftDrawing to scale
4
Motorized Methods of Harvesting• What motorized tools are used?• Sickle• Chisel• Pole Saw
• How are they powered?• Gas• DC power (battery)• AC power (cord)
• What can we use• Pole Saw• Any power solution
Sickle with chisel attachment below
Pole Saw
Not available in USA
Ricardo
5
Motorized Methods of Harvesting• Example cutting (video)
http://www.youtube.com/watch?v=qh9TP0Vzc1k
Ricardo
6
Example Pole Saw• Black and Decker 20V Max Lithium Ion Pole Pruning Saw
• $133.09 on Amazon.com• Up to 100 cuts • Cuts up to 6” thick branches• 8” long cutting bar• Pole can extend 6.5 – 10ft• Includes battery & charger• http://amzn.com/B00AZW9Y8C
Ricardo
7
Using a Pole Saw in Design• Assuming Pole Saw
• Power TBD
• Supported at pivot joint
• Potential DOF• 1 – Vertical rotation• 2 – Horizontal rotation• 3 – Horizontal Translation
1
2
3
Liam
8
DOF 1 – Vertical Rotation• Torque requirement• Up to 4lbs required at tip• 20ft-lbs of torque required w/o balance mass
• How to rotate the bar• Connect chain on two sides of pivot• Connect chain to DC motor on support• As DC motor rotates, it rotates the arm
• Use geared DC motor
•DC motor • Traxxas Titan 550 Size Motor (12T)• http://tinyurl.com/ocdo6ab • $21.99
• Gear set to make gearbox◦ Tamiya Spur Gear Set TT-01 #53665◦ http://tinyurl.com/o2efvwe ◦ $15.23
Liam
Up to 5ft
~4lbs
20ft-lbs
Need up to20ft-lbs torque
Support
DC Motor
Chain
Cutting Arm
Pivot joint
9
Potential DC Motors • 2 – Horizontal rotation
• Overcome friction to rotate
• Use Lazy Susan below support
• http://amzn.com/B0006LBVDI
• $5.71
• How to rotate
• Use Geared DC motor
• Fourbar-crank slider mechanism
• Produces about 90° rotation
2
Liam
Range of motion ~90 degrees
Rotating platform
(lazy susan)
DC motor + Linkage
Lazy susan
10
Potential DC Motors •3 – Horizontal Translation
• Overcome friction to translate
• Use low-friction sliding joint
• Also use a linear actuator
• (still being worked out)
3
Liam
11
Would it work?
2 – DOF PROTOTYPE
• 1:8 scale prototype
• Vertical and horizontal rotation
• Still needs translation
• Spent under $100 for materials
• http://youtu.be/4uAnkyqshMU
• It works!
Liam
1
2
12
Cart Design• More cost-effective to modify a pre-made cart than make it from scratch
•Large, soft wheels will be mounted to extension arms for increased cart stability
•Pole may fold down (still being worked out)
•Display and controls will be elevated for ergonomics
•Power supply sits on bottom shelf of cart
Liam
Monitor & cutting tool controls
Telescoping Pole
Modified Cart
Extended wheels
13
Example Tires for the Cart Low Speed Industrial Tires
Diameter: 10.6”
Sidewall: 3.5”
Width: 4.10”
Rim: 4”
Cost: $33.70 x 4 ~ $134.80
Load Capacity : 250lb
http://www.gemplers.com/product/10916/410-350x4-2-ply-Stud-Tire-Wheel-Assembly
Liam
14
How Telescoping Works• Telescoping is performed with pulley system
• Electric winch raises entire mast in under 1 minute
• Poles are made of PVC, with steel supports in critical regions
• Tracks will be used to keep poles radially aligned
• Electric winch: $80• 2000 lb capacity, used for ATVs• Corrosion resistant• Pulls at 13.3 ft/min unloaded
http://youtu.be/7qwizZdSHg0
Liam
Electric Winch
SteelCable
15
Camera• Needs to be waterproof
• Needs to be durable
• Needs to have a simple connection
• Good option is car camera for monitoring accidents
• http://amzn.com/B005CTKYB4• $13.64• Simple RCA cable• Waterproof• 12VDC 60mA (.72W)
Liam
16
Camera Connects to Monitor• Monitor also needs to be waterproof
• Needs to be durable
• Needs to connect to camera
• Good option is monitor used to record traffic accidents
• http://amzn.com/B007SLDF7O • $30.40• Will require waterproof case• 12VDC• 8W
Liam
17
Waterproofing• Simple to have wires hang outside of pole
• Want to prevent tangle
• Also want waterproofing
• Solution is to use coiled hose that can attach from top to bottom
• One example is http://amzn.com/B000NIYT6K
• $30.00
• 50ft long
• About 0.3” diameter
• Fit all power cables inside*
Liam
*May need to be cut into sections to help push wire through all 50ft
18Liam
Drawing not to scale
19
2 Power Configurations
David
Power Draw Options
Option 1 (~1300W)
Pole Saw (~800W)
DC Motors (~500W)
TV + camera (~10W)
Option 2 (~500W)
DC Motors (~500W)
TV + Camera (~10W)
*Pole Saw uses its own power supply (e.g. battery)
20
Selected Power Configuration
David
• Select Option 2• Camera and monitor • DC motors• Add up to ~500W
• Pole Saw will be powered independently
21
Generator as Power Supply• Sunpentown TG-1000CA
• $133.99
• Supplies 1000W of power
•PROS• Lasts up to 6hrs• Gas is everywhere• Outputs AC/ DC
•CONS• Actual output no more than 900W• Heavier• Noisier • Produces emissions
David
Battery as Power Supply• 12VDC car battery
•$75.99
•35 Amp Hour (420W-hr)
•http://www.harborfreight.com/12-volt-35-amp-hour-sealed-lead-acid-battery-68680.html
•PROS• Easy to replace• No max. power output• Instant power on• Outputs to DC components directly• Quiet
•CONS• Has to be recharged• Runs out quicker than generator
20David
23
Select Generator• We own a generator already
• Palm harvester needs to be used for 6 – 8 hours nonstop
• Generator supplies 6 hours before requiring more gas
• 1 battery would supply about 50 minutes
David
Screen DesignWhen designing our computer display monitor, there were two main factors that we took into account in order to have a safer process.
•Flicker: 75 Hertz or higher.
•Resolution: character size range of .116” to 0.128” for a reading distance of 20”.
24Bolivar
25
Screen Selection•Contrast between the character and background should be at least 3:1.
•Refresh rates should be greater than 75 Hz.
•Resolution should be pixel ratio 0.28mm or better.
•Dark letters on a white background is preferred.
Bolivar
26
Screen Location•Optimal viewing distance, from the eyes to the screen: 18 to 30” for operators without vision correction.
•Screen tilt or inclination from the horizontal: -15” to 15”.
•Top of the screen should be at eye level.
Bolivar
27
Control Design•For two out of the three motions of our design, we are going to be using spinning knobs.
•Range of adjustment is one full turn or more.
•For the cutting motion, it is better to use a hand push button with no more than 2 lb of force.
•It is recommended to use elastic resistance (spring-loading) plus slight sliding friction.
Bolivar
28
Consequences of Poor Control Design, Selection, Location•If motion stereotypes are not observed, injury potential increases.
•If controls are not coded and labeled properly, the operator may use the wrong control at the wrong time resulting in an error or injury.
•If controls are not arranged properly, search time and number of errors may increase.
•The worker’s safety might be put at risk.
Bolivar
29
Human-Cart Interface •Shoulder height
•Design the cart and the wheels such that the force applied by the worker does not surpass 48lb for the initial push and 31lb for the sustained force.
•The worker will operate the machine at a position with no potential danger.
Bolivar
30Bolivar
31Bolivar
32Bolivar
33
Next Steps• Finish scaled cutting tool prototype (A)
• Create scaled telescoping pole prototype (B)
• Create scaled cart prototype (C)
• Assemble scaled prototype (A + B + C)
• Carry out Machine Design
• Finalized part/budget list
Ricardo
34
Remaining Fall Schedule
Ricardo
35
Questions