TCNJ ELECTRIC TRANSPORT VEHICLE
SENIOR PROJECT 1 DESIGN
Brian Broderick
Phillip Cap
Brian Migliore
Kevin Weld
Advisors:
Professor Sepahpour
Dr. Asper
Student Advisor:
Matthew Rawson
PROJECT OVERVIEW
Create a zero-emissions vehicle with the ability to transport
elderly and handicapped around paths on TCNJ campus
• Solar-electric
• Cruising Speed: 15 mph
• Passenger Capacity: 8
• Utility
• Wheelchair accessibility
• Cargo storage
• Weight
• Curb Weight – 1500 lbs
• Total Weight – 3100 lbs
• Dimensions
• Length = 124”
• Width = 44”
• Run Time: Continuous 2 hours
2
TCNJ ELECTRIC TRANSPORT VEHICLE
3
AGENDA
• Frame and Braking – Phillip Cap
• Steering and Suspension – Kevin Weld
• Drivetrain and Electrical – Brian Migliore
• Anthropometrics, Ramp, and Canopy – Brian Broderick
4
FRAME AND BRAKE DESIGN
Phillip Cap
CURRENT FRAME DESIGN
6
FRAME DESIGN
Design Constraints
• Support weight of passengers and components
• Allow space for subsystems
• Able to operate on all the paths within the TCNJ campus
• Comply with ADA regulations
7
POTENTIAL DESIGNS
3-Wheeled Drive Vehicle with Trailer
• High stress on rear wheel
4-Wheeled Drive Vehicle with Trailer
• Trailer adds:
• Weight
• Complexity
4-Wheeled Integrated Vehicle
• Reduces weight and complexity
• Ladder frame style design
8
BEAM SELECTION
Beam Evaluation
I-Beam
Square Tubing
Rectangular Tubing
Bending Resistance
9
7
8
Torsional Resistance
5
7
8
Availability
5
7
7
Cost
6
7
8
Strength to Weight Ratio
8
6
7
Total
33
34
38
9
MATERIAL SELECTION
Material Evaluation
Aluminum 6061-T6
AISI 1018 Steel
ASTM A36 Steel
ASTM A513 Steel
Strength
5
7
7
8
Weldability
4
8
8
7
Corrosion Resistance
8
6
6
6
Fatigue Resistance
5
7
7
8
Weight
8
6
6
6
Cost
5
6
7
7
Availability
5
6
6
8
Total
40
46
47
50
10
BEAM OPTIMIZATION
Initial Hand Calculations
• Preliminary beam section dimensions
• 2” x 1.5” x 1/8”
Stress Analysis in SolidWorks
• Varied section dimensions
• Reinforced critical locations
11
STRESS ANALYSIS
12
BRAKE DESIGN
Design Considerations
• Safety of passengers and pedestrians
• Reliable
• Adequate stopping power
• Easy to maintain
13
BRAKE SELECTION
Brake Evaluation
Mechanical Disc
Hydraulic Disc
Hydraulic Drum
Stopping Power
4
8
7
Installation
7
5
7
Reliability
5
8
8
Cost
9
6
7
Total
25
27
29
14
STEERING AND SUSPENSION
Kevin Weld
SUSPENSION DESIGN
Design Constraints
• Minimize ride height
• Comfortable range of oscillation frequency
• Variable load
16
POTENTIAL DESIGNS
Independent Suspension
• MacPherson Strut
• Torsion Bar
• Transverse Leaf Spring
Solid Axle Suspension
• Coil over Shock
• Longitudinal Leaf Spring
17
DECISION MATRIX
Suspension Evaluation
Leaf Spring
Double A-Arm
Torsion
Bar
None
Cost
8
5
7
10
Manufacturability
7
5
7
10
Size
6
5
8
8
Utility
8
10
7
0
Total
29
25
29
28
18
WEIGHT DISTRIBUTION
All weights in lbs
WV (weight of
vehicle)
W1 (driver and
passenger)
W2 (front
bench
passengers)
W3 (rear
bench
passengers)
W4 (far rear
passengers)
Front
spring
design load
Rear spring
design load
1500
200
0
0
0
521
329
1500
400
0
0
0
621
329
1500
400
200
0
0
704
346
1500
400
400
0
0
787
363
1500
400
400
200
0
839
411
1500
400
400
400
0
891
459
1500
400
400
400
200
898
552
1500
400
400
400
400
904
646
19
LEAF SPRING OPTIONS
Ride Height
(in)
Maximum
Natural
Frequency
(Hz)
Spring Description
Source/Part No.
Max Capacity (provided
by manufacturer) (lb)
Deflection at
1000 lb load
(in)
20" Double Eye
Leaf Spring (3
leaves) #US-1007
Eastern
Marine/5266002
1500
0.565
2.935
7.60
20" Double Eye
Trailer Leaf Spring
(4 leaves) #US1008
Eastern
Marine/5266001
1000
0.794
2.206
6.41
25-1/4" Double Eye
Trailer Leaf Spring
(3 leaves) #US1035
Eastern
Marine/5266091
1500
1.137
1.863
5.36
23-1/8" Double Eye
Leaf Spring (3
leaves) #US-1014
Eastern
Marine/5266065
1250
0.874
2.126
6.11
26" Double Eye
Trailer Leaf Spring
(2 leaves) #US1013
Eastern
Marine/5266008
1000
1.345
2.905
4.92
20
FRONT AXLE DESIGN
Outside Box Size (in)
Wall Thickness (in)
Stress (psi)
Factor of
Safety
1.75
0.083
15323
3.00
1.75
0.12
11304
4.07
2
0.065
14317
3.21
2
0.083
11522
3.99
21
INTEGRATED FRONT SUSPENSION
22
STEERING DESIGN
Design Constraints
• 10 ft steering radius
• Avoid skipping
• Ackermann steering angle
23
POTENTIAL DESIGNS
Six Bar Linkage
Rack and Pinion
24
STEERING AXIS ORIENTATION
Steering Axis Inclination – 15 degrees
Caster Angle – 5 degrees
25
INTEGRATED STEERING DESIGN
Sprockets – mechanical advantage: 1.875
26
DRIVETRAIN DESIGN
Brian Migliore
DRIVETRAIN COMPONENTS
Single Motor
Motor Controller
• Brushed DC Series Wound
• Intuitive and perceptive
• High Torque
• Anyone should be able to operate
this vehicle
Battery Powered
• Zero-Emissions Green Vehicle
• Lead-Acid
Charging
• On Board Charger
Rear-Wheel Drive
• Direct Drive
• Large Differential Reduction
• Strong Rear Axle
• Solar Panels on Canopy
28
POWER FLOW CHART
29
MOTOR CONSIDERATIONS
Drivetrain Parameters
• Cruising Speed of 15 mph
• Time to Top Speed = 3 seconds
• Total Torque Needed = 512 ft-lbs
• Total Power Needed = 4 kW
• 16.5 Inch Diameter Tire
DD Motor Systems – ES-63-49
• 19 Tooth Female Spline
• Peak Power
• 65 ft-lbs
• 1,625 RPM
• 20.1 HP
• 500 Amps/Armature
• S2 – 30 Min
• 12 ft-lbs
• 2,650 RPM
• 6.05 HP
• 115 Amps/Armature
30
BATTERY DESIGN CONSIDERATIONS
Desired Qualities
• 48 Volts
• Deep Cycle
• Industry Standard
Li-Ion Battery Performance
• Greater Cycle Life / Discharge Rate
• Li-Ion Battery use will save
• 51.5% Reduction in Weight
• 31.1% Reduction in Volume
• Cost 2.5 times Lead-Acid
31
BATTERY CHOICE
Trojan T-105 (Lead-Acid)
• 6 Volt Deep Cycle Battery
• 225 Ah @ 20Hr Rate
• 62 lbs per Battery
Trojan T-105 Performance Curves
32
CONTROLLER CONSIDERATIONS
Design Parameters
• Programmable – Depending on batteries this will help prevent any damage
to power source
• Possible to use an electronic reverse for DC series wound motor
33
CONTROLLER CHOICE
Curtis Model 1268 - 5502
• 48 Volts, 500 Amp Max Power Rating
• Industry name, effective, safe, and tested design
• Speed sensor allows closed loop control for regulating speed of vehicle
• Acceleration and braking of throttle can be programmed
• Electronic Reverse is included
• Diagnostic tools and codes to alert of any issues
34
CHARGING CONSIDERATIONS
Design Parameters
• Programmable to display errors and/or warnings during charging
• Charge at certain voltages and current
• Prevents over-voltage
• Prevents over-heating of batteries
• Small and portable enough to fit on-board vehicle
• Eagle Performance Model i4818
• 48 Volt Charger
• LED Charge Indicator
• Auto Off/Auto On Trickle Charge
• 9.75” x 8.38” x 8.25”
35
DIFFERENTIAL CONSIDERATIONS
Decision Matrix
Weight:
Option
EZ-GO 2
Person Axle
Titan HD
Axle
20%
30%
30%
10%
10%
100%
Weight
Strength
Gear
Ratio
Cost
70
50
70
80
20
60
50
90
90
40
20
70
Maintenance Score
Titan HD Axle – Model #600185G02
• 14.76 : 1 Differential Gear Reduction
• Includes 7” Rear Brake Drums
• 4 on 4 Brake Stud Alignment
• 19 Tooth Male Spline
36
REAR AXLE ASSEMBLY
37
ANTHROPOMETRICS, RAMP DESIGN, AND
SOLAR CANOPY
Brian Broderick
ANTHROPOMETRIC DESIGN
Design Goals
• Minimize loading/unloading times
• Meet ADA standards for wheelchair accessibility
• Maximize Passenger Capacity
• Maximize Comfort
39
POTENTIAL DESIGNS
Conventional Golf Cart
Mid-Chassis
Wheelchair Accessible Golf Cart
40
PROPOSED DESIGN
8
Passengers
7 Passengers
Including 1 Wheelchair Patron
ADA Designated
Areas shown in Red
41
DECISION MATRIX
Anthropometric
Evaluation
Traditional Golf
Cart -Limo
Mid-Chassis
Wheelchair
Rear Wheelchair
Cost
7
6
4
7
6
4
0
10
10
Accessibility
6
7
8
Capacity
7
5
9
Total
27
34
35
Manufacturability
Wheelchair
Accessible
42
SEAT SPACING
95th Percentile
Dimensions
43
ALTERNATIVE SEATING DESIGNS
EZ GO TXT Complete Seat
Springfield Low Back Folding Seat
44
FINALIZED DESIGN
Custom Wooden Seats
• Wood Rib Design
• 3” Foam
• Vinyl Fabric
Bottom Seat Assembly
Back Support
45
DECISION MATRIX
Front and Middle Seats
Seat Evaluation
Cost
Manufacturability
Comfort
Fit
Total
EZ GO TXT
Complete Set
Custom Made Springfield Low
Seats
Back Folding Seat
5
7
8
8
4
10
7
9
6
5
10
1
25
30
25
Rear Seats
Seat Evaluation
Cost
Manufacturability
Folding Capability
Fit
Total
EZ GO TXT
Complete Set
Custom Made Springfield Low
Seats
Back Folding Seat
3
5
8
10
5
10
0
0
10
7
10
9
20
20
37
46
RAMP DESIGN
Design Constraints
• Minimize obstruction of pathways
• ADA Standards
• Provides additional restraint
24”
2”
24”
4”
2”
47
POTENTIAL DESIGNS
Side Folding, Bi-Fold ramp
24”
2”
24”
4”
2”
Tri-Folding, Rear Ramp
48
PROPOSED DESIGN
Rear-loading Bi-fold Ramp
24”
2”
24”
4”
2”
49
CANOPY DESIGN
Design Considerations
• Provide shelter
• ADA Compliance
• Solar Panel Incorporation
24”
2”
24”
• Lightweight
4”
2”
50
ALTERNATIVE DESIGNS
Pre-Made Stretch Plastics Top
24”
2”
24”
4”
2”
Custom Split Level Aluminum Top
51
FINALIZED DESIGN
Custom Flat Aluminum Top
24”
2”
24”
4”
2”
52
TOTAL BUDGET
Subsystem
Cost
Frame
$531.55
Suspension
$795.50
Drivetrain
$5,609.77
Steering
$332.42
Braking
$735.84
Seating
$723.19
Canopy
$802.08
Ramp
$424.13
ADA/Misc
$526.53
Total
$10,481.01
53
GANTT CHART
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TCNJ ELECTRIC TRANSPORT VEHICLE
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TCNJ ELECTRIC TRANSPORT VEHICLE (ETV)
SENIOR PROJECT 1 DESIGN
Comments or Questions?
Brian Broderick - Manager, Anthropometrics, Ramp, Canopy
Phillip Cap - Frame, Braking
Brian Migliore - Drivetrain, Electrical
Kevin Weld - Suspension, Steering
Advisors:
Professor Sepahpour
Dr. Asper
Student Advisor:
Matthew Rawson
56