powertrain decisions - ohio.edu · slide 3 powertrain components motor controller chain vs. belt...

Dan Tyburski

Brian Marlow

Philip Poll

Jason Gray

Matt Decker

Julio Cumba

Chris Short

Katie Melton

Mike Caples

Eric Krouse

TJ Cyders

Craig Foglesong

Adam Koloff

Adam Shank

Chris Williams

Jared Donnamiller

Powertrain DecisionsPowertrain Decisions

Vehicle Design

Controls, Seating, and Ergonomics

Frame andSuspension

Powertrain T.J. Cyders

Chris ShortJared Donnamiller

Phil PollEric KrouseKatie Melton

Chris Williams

Jason GrayAdam Koloff

Adam Shank

Mike CapelsBryan Marlow

Matt DeckerDan Tyburski

Team Breakdown into SubsystemsTeam Breakdown into Subsystems

Julio Cumba

Craig Foglesong

Powertrain ComponentsPowertrain ComponentsMotor

Controller Chain vs. Belt Drive

Batteries

T-ChartAnalysis

CustomerEvaluation

MatLABProgram

Excel Spreadsheet

Vendor ContactBenchmarking

MatLABProgram

Excel Spreadsheet

MotorMotor

Considerations SpecificationsMax speed of 19.5 mph20 miles in a 14 hour period Ascend 10% grade for 1/8 mile15 mph up a 5% gradeAccelerate at 1.5 m/s²Manufactured in lots of 5000/ yr

PerformanceAvailabilityWeightCostCompact Size

Motor ConsiderationsMotor Considerations

Etek PERM D & D24 - 48V

6.7 x 8.6

38.0 lbs.

PEAK HP 48v 15.0 hp 15.1 hp 20.0 hp 4.5 hp (24v)

COST $595 $949 $550 $350

LOCATION Wisconsin Germany New York Florida

MagmotorVOLTAGE RANGE 24 - 48V 12 - 72V 12 - 24V

SIZE (Dia. x L) 7.9 x 5.6 8.7 x 6.4 2.8 x 6.4

WEIGHT 20.8 lbs. 24.8 lbs. 6.8 lbs.

Briggs & Stratton Etek48V DC 3400 rpm optimum speedAvailable in necessary quantities

ConcernsMeets all specificationsMounting options

Choice of MotorChoice of Motor

Powertrain: Motor SelectionPowertrain: Motor Selection

Estimated power requirements: Worst case

0 5 10 15 20 25 300

1

2

3

4

5

6

7

8

9

time [s]

velo

city

[m/s

]

Power over a 30-second drive cycle

velocity [m/s]power [Hp] @ 250kg

0.5

1

1.5

2

2.5

3

3.5

4

Pow

er [H

p]

1.5

m/s

2

19.5 mph, 0 slope

15 mph,

5% slope10 mph,

10% slope1.67 Hp10%

1.45 Hp5%

.58 Hp0 slope

2.18 HpAccel.


Revised drive cycle5 complete cycles

0-10 mph X3

10-19.5 mph X6

Slope 5.00% 15 mph ½ mi

Slope 10.00% 10 mph 1/8 mi

0 slope 19.5 mph 1.25 mi

Accel. 3.35 mph/s (1.5 m/s2)

Accel. 1.12 mph/s (0.5 m/s2)

Steady-State


Estimated torque requirements:

0 5 10 15 20 25 30 35 400

2

4

6

8

10

12

time [s]

velo

city

[m

/s]

Torque over a simulated drive cycle

Torq

ue [

Nm

], C

urre

nt [

A]

velocity [m/s]Torque [Nm]Amps

20

40

60

80

100

120

.5 m/s^

2

1.5

m/s

^2

5% slope

10% slope

Zero Slope

Motor PerformanceMotor Performance SimulationSimulation

Differential equation increases accuracy

⎥⎥⎥⎥

⎦

⎤

⎢⎢⎢⎢

⎣

⎡ +−=

m

FFRT

dtdv resistdrag

w

w )(

Confirms Etekmotor is capable of fulfilling specifications

Chain vs. Belt DrivesChain vs. Belt DrivesChain Drive System Belt Drive System

• No slippage between chain and sprocket teeth (1)

• Operates in hostile environments such as hightemperatures, oily, dusty, high moisture areas (2)

• Long operation life (4)

• Can replace one linkage as opposed to a whole belt (8)

• Quiet operation (3)

• Belts dampen sudden shocks or load changes (5)

• Minimal/ infrequent maintenance (6)

• No lubrication required (7)

Adv.

• Flexibility limited to a single plane

• Relatively higher noise levels

• May elongate due to link and/ or sprocket wear

• Slippage can occur, particularly with improper belt tension

• Wear of belts, sheaves, and bearings can reduce tension

• Does not operate well in adverse service environments (extremetemperatures, oily atmospheres)

• Length cannot be adjusted

Dis.

Premature Tooth Wear

Low Sprocket HardnessExcessive Debris

Improper Sprocket Material

ImproperLubrication

ParticleContamination

Fault Tree (Visual) AnalysisFault Tree (Visual) Analysis

Misaligned Drive

Improper DriveDesign

FMEA AnalysisFMEA Analysis-- Chain DriveChain Drive

Potential Failure Modes:1) Chain Vibration or Whipping2) Premature Tooth Wear3) Chain Jumps Sprocket Teeth4) Noisy Drive 5) Tight Joints in the Chain6) Tensile Chain Break7) Failure Pins, Rollers, Bushings8) Failure of Chain Linkplates

Severity of Failure:5

•No danger of physical harm•Will hinder performance and/ or cause the vehicle to become inoperable if not addressed

Probability of Failure:4

• Unprotected drive• Improper tensioning

Detection:4

• Excessive noise willbe indication of whipping

Prevention:4

• Protective covering and proper maintenance

• Proper installation

Sprocket at MotorType B, No. 40, ½” PitchStainless Steel12 Teeth0.50 lb.2.170” O.D.~ $15

Sprocket at Rear WheelType A, No. 40, ½” PitchStainless Steel60 Teeth5.50 lb.9.840” O.D.~ $40

No. 40 Chain½” Pitch836 lb. max. loadMeets ANSI standards$20 per 10 ft.

Only require 5 ft.~3.5 lb. per 5 ft

120 Deg. Min.

Cost & Weight Summary

Cost Weight

Motor Sprocket $15 0.5 lb

Rear Wheel Sprocket $50 5.5 lb

Roller Chain $20 3.5 lb

Total $85 9.5 lb

Where Do We Go Next ?Where Do We Go Next ?Continuous communication with Frameand Controls subgroups• Motor mounting

• Chain/ Sprocket relationship

• Optimum battery and controller location

Customer Evaluation

• Most accessible locations for maintenance

• Beneficial placement for rider comfort

Analysis• Fault Tree Analysis – In progress

• FMEA Analysis – In progress

• FEA Analysis – What and Why

Questions ?????Questions ?????


Simulation Assumptions:Mass 550 lb (250 kg)

Coefficient of Drag 0.5

0.1

Air Density

Wheel Radius 6.25 in (0.159 m)

Gear Ratio 5:1

Coef. Rolling Resistance

4.34x10-5 lb/in3 (1.2 kg/m3)

wmotor

w

resistdragw

w

Rsloperollresist

Ddrag

TTN

tKEIVP

mvKE

vat

m

FFRT

dtdv

slopeCmgFFF

AvCF

ωω

ρ

==•

==•

=•

=•

⎥⎥⎥⎥

⎦

⎤

⎢⎢⎢⎢

⎣

⎡ +−=•

+=+=•

=•

2

2

21

)(

)(2

Current DrawCurrent Draw

Current draw from 5 drive cycles

Based on torque requirements, gear ratio and motor torque constant:

118 A 45 s

80 A 3.75 min

50 A 5 min

30 A 10 min

13 A 20 min

Tgear

wheel

kNTI =

N= 5:1

kT=.13 Nm/A (Etek motor)

BatteriesBatteries

Why we are using a 48 v system-Keeps the current low24 v would require the use of high current capable batteries like NiMH. Motor characteristics yield a bit more powerWon’t deplete the batteries as much

http://www.batterybus.com/item_details.asp?id=13034.1

BatteriesBatteries

+NiMH

+ -Volt. Reg. Lead Acid

Low weight

High current capable

Disposable

High cost

Many needed

Complex charging

Proven technology

Low cost

Simpler charging

Many manufacturers

Recyclable

High weight

Nonlinear current char’s

-

Battery ComparisonBattery Comparison

VRLA NiMHCharging

ComplexityLow High

Cost/Vehicle $120 $1500

# Needed 4 160

Recyclable Yes No

Weight 106 lbs. 52 lbs.

Final Battery DecisionFinal Battery Decision

Controller SelectionController Selection

Requirements24-48 VDC operational range>300 Amp peak currentProgrammabilityCurrent limiting capabilityRegenerationBuilt-in safety featuresCost

Controller ComparisonController Comparison

Navitas 4QD AlltraxNO

Included

400A

VOLTAGE 24-48V 24-48V 24-48V 24-48V

SAFETY YES Some YES Optional

COST $595 $490 $395 $595

LOCATION Ontario Florida Oregon Massachusetts

SevconREGEN YES YES YES

PROG. Included Minimal Optional

MAX I 400A 320A 325A

Selected ControllerSelected Controller

Controller Selection: Navitas TPM 400

24-48VDC, 400 Amp (peak) 4 Quadrant OperationBuilt-in safety features

Thermal and over-current protectionSpeed limiting (forward and reverse)Power-up diagnostics and “safe sequencing”Programmable via PC interface (included)

What is programmable mean?

powertrain decisions - ohio.edu · slide 3 powertrain components motor controller chain vs. belt...

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