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Imperial International Journal of Eco-friendly Technologies
Vol. - 1, Issue-1 (2016), pp.153-165
IIJET
153
RESEARCH REPORT ON ECOFRIENDLY
VEHICLES V.ANIL KUMAR
*, CH.RAMA KRISHNA
**, CH.AMARNATH
***,
HARSHAVARDHAN REDDY M****,
V.S.V.V.RAJ AKHIL*****
****[email protected],
*****[email protected]
The fuel consumption for the human need has increased
enormously from last 2-3 decades and due to this, there is a
massive increase in pollution. And also, the increase in fuel
prices will ultimately affect the livelihood of human race.
To overcome this problem and also to give human
conveniences, hybrid systems have been developed, which
will not only decrease the fuel consumption but also Eco-
friendly.
In our project while manufacturing a hybrid vehicle which
will run simultaneously on IC engine as well as the electric
motor, Power will be regenerated by using a dynamo when
the vehicle is in operation.
Abstract
In general, there are three types of hybrid systems
(based on engine motor shaft alignment) available in
our market. Series hybrid, Parallel hybrid and Series-
Parallel hybrid systems. We have preferred parallel
hybrid system and made few modifications to it , To
overcome the drawbacks. One such major modification
is usage of dynamo along with regenerative braking for
increasing alternate energy production. The main
reason for making such change is the more efficient
production of energy by dynamo in long run when
compared to that of regenerative braking which is
restricted to city life. This makes our vehicle more
efficient when compared to that of vehicles using
Parallel hybrids and other types, since it adds the extra
alternate energy produced by that of dynamo in
running condition.
I. Manufacturing process
In the process of manufacturing a hybrid vehicle, the
processes involved are:
Designing
Manufacturing
Simulation
A. Designing & Manufacturing
We have designed the chassis on CATIA, as it was user
friendly and also we have done analysis by taking the
material AISI 1018 as it has yield strength 320 MPA and
ultimate strength 450 MPA which has a high strength while
comparing with other materials
YOUNG’S MODULUS 210 GPA
STRENGTH TO WEIGHT
RATIO 55-60 Kn-m/kg
Thermal expansion 11.9 um/m-k
DENSITY 7.8 g/cm^3
The chassis design is
Imperial International Journal of Eco-friendly Technologies
Vol. - 1, Issue-1 (2016), pp.153-165
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The actual chassis we have developed is shown below:
Fig. 1: actual chassis we have developed
II. Results
By doing analysis to the designed vehicle on CATIA of
front impact and rear impact, the results are:
A. Front impact
Front impact test is to check the survivability of the chassis
during a frontal impact.
Deflection=1.00224mm, Maximum stress: 165.032 MPA
B. Real impact
Rear impact test is very similar to the front impact but in
this case vehicle is considered to be movable so during
Imperial International Journal of Eco-friendly Technologies
Vol. - 1, Issue-1 (2016), pp.153-165
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impact the vehicle experience less G-Force than front
impact test.
Deflection: 6.86038 mm; Maximum stress: 294.22 MPA.
C. Side test
During a side impact the vehicle experiences
approximately half of the force that it experience during
front impact.
Deflection: 9.40154 mm; Maximum stress: 281.46 MPA
D. Torison test
In torsion test the back member where the arms are placed
are fixed and torsion is applied on it.
Deflection: 8.08424 mm; Maximum stress: 194.244 MPA
III. Transmission
In the part of transmission of the vehicle while fulfilling
the requirement of vehicle have to be run on both IC engine
and motor we have decided to use the parallel hybrid
system as it was most efficient and also the engine shaft
engages with clutch, gear box and differential setup used in
Bajaj auto which has four variable speeds of gear
reductions. And the motor is directly mounted on the shaft
by using a free wheel which is based on the mechanism
Ratchet-Pawl. Which will transfer power only on one
direction and reverse direction of power transmission is
restricted by using this type of free wheels.
The engine and motor that we have used the specifications
are:
1. Engine
2. Motor
Imperial International Journal of Eco-friendly Technologies
Vol. - 1, Issue-1 (2016), pp.153-165
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A. Engine mounting
Engine is directly mounted to the clutch shaft in which
both the gear box and differential had in a single setup.
FIG. 2: -actual engine mounting we have made
B. Motor mounting
Motor is directly mounted on the output of differential
shaft by a free wheel connected through chain sprocket.
The motor speed is controlled with motor controller by
using a foot pedal.
III. Suspension
Suspension is the term given to the system of
springs, shock absorbers and linkages that
connects vehicle to its wheels.
Introduction to suspension system:
o To maintain good contact between
wheels and road surface.
o To maintain good ride height.
o To increase the stability of car during
ride.
o To provide good comfort to the
passengers.
As per our requirements we chosen
Front double wishbone suspension (damper to
rocker arm)
Rear double wishbone suspension (damper to
upper arm)
A. Front suspension
1. Double wishbone suspension
In automobiles, a double wishbone (or upper and lower A-
arm) suspension is an independent suspension design using
two wishbone-shaped arms to locate the wheel.
B. Design and analysis of suspension parts
1. A arms
In automotive suspension, a control arm, also known as
an A-arm, is a hinged suspension link between
the chassis and the suspension upright or hub that carries
the wheel. Wishbones are triangular and have two widely
spaced inboard bearings. These constrain the outboard end
of the wishbone from moving back and forth, controlling
two degrees of freedom, and without requiring additional
links.
2. Front A arms Upper A ARM (designed by using CATIA software)
Length of the A arm = 307 mm
Imperial International Journal of Eco-friendly Technologies
Vol. - 1, Issue-1 (2016), pp.153-165
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Lower A arm (designed by using CATIA software)
Length of the A arm =311mm
Rear A arms: Length of a arm =319 mm
3. Suspension knuckle
A suspension knuckle attaches the upper and lower
suspension components to the wheel support assembly and
is the mounting point for the wheel spindle or hub. It is
called a “steering knuckle” if it is used in a location
requiring the wheel to turn, where the knuckle rotates on
the lower ball joint, allowing the wheels to turn left or
right.
Front knuckle (designed by using CATIA software)
Rear knuckle (designed by using CATIA software)
Springs and dampers
Springs: It absorbs road shocks or impacts due to bump in
road by oscillating.
Tires also provides spring effect, but to a smaller extent.
Dampers: They reduce the tendency of the carriage unit to
continue to “bounce” up and down on its springs
.Oscillation due to road shocks are restricted
to a reasonable level by damper.
Design of helical compression spring for shock
absorber:
Material: Music Wire (ASTM A228)
Mean diameter of a coil D=64 mm
Diameter of wire d = 8 mm
Total no of coils n = 12
Outer diameter of spring coil D0 = D + d = 72
mm
Inner diameter of spring coil Di = D - d = 56 mm
No of active turns n= 10.5
Weight of vehicle = 150 Kg (spring weight)
Let weight of 1 person = 70 Kg
Total Weight (Wt.) = Weight of vehicle + Weight
of 1 persons
= 150+70 = 220 Kg
Weight distribution bias Front/Rear= 40/60 %
40/60 % of 220 = 88/132 Kg
Considering dynamic loads (Rear) it will be
double Wt = 264Kgs = 2413 N
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Vol. - 1, Issue-1 (2016), pp.153-165
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For single shock absorber weight (W)
=Wt/2=2413/2 =1206.5 N
Spring Index = D/d = 8
Solid length Ls = n*d= 12*8 = 96 mm
Free length of spring, Lf = solid length +
maximum compression + clearance between
adjustable coils = 250 mm
Pitch of coil, P = 10.42
Damper eye to eye = 330 mm
By using these static values, we obtained:
1. Spring constant, K = 14.7 N/mm
2. Maximum displacement possible = 150 mm
3. Maximum load possible = 2200 N
4. Maximum shear stress possible = 8.31*10^8
Pa
5. Length of the wire required to make spring =
2530 mm
6. Solid height = 100 mm
7. Distance between coils in free spring = 23.8
mm
8. Rise angle of coils = 6.75 deg
9. Mass of spring = 0.999 Kg
10. Lowest spring resonant frequency = 60.6 Hz
11. Shear modulus of material ,G = 79 G Pa
Other parameters in suspension:
A. Track width
The Track width is the measurement from tire centre to tire
centre. With Twin tires, measurement is made from the
centre of the twin tire to the centre of the twin tire. This has
a significant influence on the cornering behavior of a
vehicle.
As per the requirements track width of vehicle = 1099 mm
B. Wheel base
The WHEELBASE of a vehicle equals the distance
between its front and rear wheels. At equilibrium, the total
torque of the forces acting on a vehicle is zero. As per the
requirements wheelbase of vehicle = 1465 mm
C. Roll center
The roll centre is the point about which the body can roll
without any lateral movement at either of the wheel contact
areas.
Front Roll centre = 8.242 mm
D. Motion ratio
Motion ratio in suspension of a vehicle describes the
amount of shock travel for a given amount of wheel travel.
Mathematically it is the ratio of shock travel and wheel
travel. The amount of force transmitted to the vehicle
chassis reduces with increase in motion ratio. A motion
ratio close to one is desired in vehicle for better ride and
comfort. One should know the desired wheel travel of the
vehicle before calculating motion ratio which depends
much on the type of track the vehicle will run upon.
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Motion ratio = d1/d2
= 263/330
= 0.797.
E. Anti - dive & anti – squat
Anti-dive and Anti-squat are expressed in terms of
percentage and refer to the front diving under braking and
the rear squatting under acceleration. They can be thought
of as the counterparts for braking and acceleration as Roll
Center Height is to cornering. The main reason for the
difference is due to the different design goals between front
and rear suspension, whereas suspension is usually
symmetrical between the left and right of the vehicle.
ANTI- SQUAT = 63%
F. Ride height
Ride height (also called ground clearance or
imply clearance) is the amount of space between the base
of an automobile tire and the underside of the chassis; or,
more properly, to the shortest distance between a flat, level
surface, and any part of a vehicle other than those parts
designed to contact the ground (such as tires, tracks, skis,
etc.). Ground clearance is measured with standard vehicle
equipment, and for cars, is usually given with no cargo or
passengers.
Ground clearance of vehicle = 8 cm
G. Bump steer
Bump Steer is when your wheels steer themselves without
input from the steering wheel. The undesirable steering is
caused by bumps in the track interacting with improper
length or angle of your suspension and steering linkages.
Most car builders design their cars so that the effects
of bump steer are minimal.
H. Weight distribution
Weight transfer customarily refers to the change in load
borne by different wheels during acceleration. This is more
properly referred to as load transfer.
Kerb weight on front axle = 40%
Kerb weight on rear axle = 60%
3. Suspension parameters
A. Camber
Camber angle is the angle made by the wheels of a vehicle;
specifically, it is the angle between the vertical axis of
the wheels used for steering and the vertical axis of the
vehicle when viewed from the front or rear. It is used in the
design of steering and suspension.
As per our requirements camber angle = 3 deg (negative)
B. Caster
The caster angle or castor angle is the angular displacement
from the vertical axis of the suspension of a steered wheel
in a car, motorcycle, bicycle or other vehicle, measured in
the longitudinal direction.
As per our requirements caster angle = 5 deg (positive)
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C. Toe-in:
In automotive engineering, toe, also known as tracking, is
the symmetric angle that each wheel makes with the
longitudinal axis of the vehicle, as a function of static
geometry, and kinematic and compliant effects. Positive
toe, or toe in, is the front of the wheel pointing in towards
the centre line of the vehicle
As per our requirement toe-in = 10 mm
Fig. 1: actual wishbone suspension we have
developed
Steering
A. Introduction
The controlling behavior of a vehicle is influenced by the
performance of its steering system. The steering system
consists of steering wheel, steering column, rack and
pinion steering box, tie rods, and universal joint. Our
vehicle is controlled by movement of pinion over rack and
this motion is transmitted through tie rods into the steering
knuckles.
We have chosen to incorporate Ackermann mechanism as
it was universally due to its simplicity
Ackerman is the difference in turn radius between the front
tires. The Ackerman can help the car turn better through
the center of turn.
The relationship between inner wheel angle and outer
wheel angle
Cotα – cotβ =w/l
Where α= outer wheel angle,
β=inner wheel angle,
w=track width,
l=wheel base.
MECHANISM OF RACK AND PINION STEERING
SYSTEM
As a steering wheel is turned, it spins the pinion
over the rack, centrifugal force slides rack back
and forth. Tie rods are connected to each end of
rack, which activate the steering arms. Steering
arms are connected to each wheel, and cause them
to turn.
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For our convenience we take steering ratio as
10:1.
ACCORDING TO ACKERMAN GEOMETRY,
Ackerman geometry is closely approximated by a
trapezoidal arrangement the asymmetry in geometry causes
inner wheel steer to greater angle than the outer wheel.
From the above
Inner wheel angle, β=38.5 deg
Cot α-cot β=w/l
Cotα-cot 38.5=1099.05/1465.4
Outer wheel angle, α =26.48 de
KINGPIN INCLINATION
The kingpin is set at an angle relative to the true vertical
line, as viewed from the front or back of the vehicle. This
is the kingpin inclination or KPI (also called steering axis
inclination, or SAI).SAI is non-adjustable.
SCRUB RADIUS
The scrub radius is the distance in front view between the
king pin axis and the center of the contact patch of the
wheel, where both would theoretically touch the road.
SPECIFICATIONS
Track width 1099.05 mm
Wheel base 1465.4 mm
Steering arm length 100 mm
Steering arm angle 20.6 deg
Steering ratio 10:1
Inner wheel lock 38.5 deg
Outer wheel lock 26.48 deg
Kerb weight 170 kg
Rack length 300 mm
Rack travel 130 mm
No. of turns 1.41
Weight of driver 70 kg
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Force required on
steering wheel 37.67 N
Turning radius 2457.65 mm
Tie rods lengths 364.4 mm
Tie rod inclination 15.5 deg
Steering column length 700 mm
Steering wheel
diameter 250 mm
King pin inclination 10 deg
Fig. 2: actual steering we have developed with
rack and pinion mechanism using ackermann
geometry
We have used bearing at the wheel arrangement to the
chassis.
Braking system
A. Objective
A brake is a device by means of which artificial frictional
resistance is applied to a moving machine member, in order
to retard or stop the motion of a vehicle .Most brakes
commonly use friction between two surfaces pressed
together to convert the kinetic energy of the moving object
into heat. The vehicle has two independent hydraulic
systems and it is actuated by a single brake pedal. The
pedal directly actuates the master cylinder. Here no Cables
are used for this purpose. All rigid brake pipes are mounted
securely along the roll cage or along other members.
B. Components
Brake pedal, Tandem master cylinder, brake linings,
caliper, rotor are
Suitable components of disc brake system.
C. Rotors
The disc of brakes are made of grey cast iron and
is of solid disc, as in ventilated type disc poor heat
transfer due to blocking of holes.
We use casted disc of thickness 8mm and outer
diameter of 155mm in accordance to our design.
D. Calliper
We have used a fixed type Caliper in our design.
Fixed type caliper doesn't move but has piston(s)
arranged on opposing sides of the rotor.
We have selected pulsar 220 rear calipers as it is
small enough to fit in wheel assembly & has
maximum piston diameter of 30mm.
E. Master cylinder
We have selected master cylinder of Maruti 800
which has a bore of diameter of 19.05mm.
F. Brake circuits
A brake circuit of diagonal split system is used as
in case of a failed hydraulic circuit, there are still
two brakes that provide equal braking forces. For
this reason, the vehicle won’t turn or pull in either
direction under failed-circuit braking.
G. Brake fluid
We have decided to use DOT3 brake fluid as it is
inexpensive & compatible with one another.
Design considerations
o Brake disc thickness:8mm
o Brake disc type :full
o Brake disc diameter:155mm
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Technical specifications:
o Net vertical force on
vehicle(static):2354N
o Vertical force on front(static):975N
o Vertical force on rear(static) :1379N
o % of front weight(static):41.4%
o CG height : 266mm(10.47in)
o Wheel base : 1465mm(57.67in)
o Effective disc radius=67.5mm
H. Calculations
Brake pedal:
Brake pedal is mainly intended to multiply the
force exerted by driver. Brake pedal ratio may be
taken as 7:1.
By lever ratio of brake pedal assembly
Fbp = Fdx L1/L2
Where Fbp=Force output of brake pedal assembly
Fd=Force applied to the pedal pad by driver=85lb
L1=the distance from the brake pedal arm pivot to
the output rod clevis=7
L2=the distance from the brake pedal arm pivot to
the brake pedal pad=1.
Fbp = (85x9.81x7) / (2.20462x1)
=2648N
Pressure in master cylinder:
As fluids are incompressible and infinitely rigid
hydraulic vessels, the pressure generated by
master cylinder will be
Pmc=Fbp / Amc= 2648/ (2.85x10^-4)=9.28x10^6
N/m^2
Where Pmc=Hydraulic pressure generated by
master cylinder
Amc=Area of master cylinder piston.
Forces on calliper:
o Considering no losses in brake lines the
pressure transmitted to the brake lines
will be equal.
Pcal=Pmc=9.28x10^6 N/m^2.
o Forces in caliper is
Fcal=Pcal * Acal= (9.28x10^6)*
(7.0685x10^-4)
=6566N
Where Fcal=Force generated by
caliper.
Acal=Area of caliper hydraulic piston
found one half side of the body.
o As each caliper has two clamps i.e, two
pistons in fixed type caliper , so
Fclamp=Fcal x2
=13132N
Where Fclamp=clamp force generated by
caliper.
o The clamping force causes friction which
acts normal to this force and tangential to
the plane of the rotor. The friction force
is given by:
Ffric=Fclamp * ubp
=13132x0.35
=4596.2N
o The braking torque is related to force on
brake pads friction force.
Tr=Ffric x Reff
=4596.2 x 0.0675
=310.2435 Nm.
o As brake disc is connected to hub of the
tire so, effective torque is same
considering no losses.
Tt=Tr=310.2435 Nm.
Where Tt=Torque on tire.
o Force on tire is
Ft=Tt/Rt
=310.2435/.217=1429.7N
Where Ft= Force acting on a tire.
o Total force acting on all tires is
Ftotal=4xFt x utr
=4x1429.7x.7=4003.14N
Where Ftotal=Total force acting on all
tires of vehicle.
o The deceleration of the vehicle will be
equal to
av=Ftotal / mv
=4003.14/240=16.68 m/s^2
Where av=deceleration of vehicle
mv=mass of vehicle.
o For a vehicle experiencing a linear
deceleration, the theoretical stopping
distance of a vehicle in motion can be
calculated as follows:
SD=v^2 / (2xav)
= (12.5^2)/(2x16.68)=4.68m
I. Weight distribution
In the side view, the sum of the left front and right front
weights will equal the front axle weight and the sum of the
left rear and right rear weights will equal the rear axle
weight. If these values are known, then the static weight
distribution can be calculated as follows:
Percentage front weight : Wf/Wt x 100
=981/2354.4 x100
=41.66%
Percentage rear weight: Wr/Wt * 100
=1373.4/2354.4 x100
=58.34%
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Where Wt=Total vertical force (weight)
Wf=Front axle vertical force (weight)
Wr=Rear axle vertical force (weight)
J. Weight transfer
Whenever a vehicle experiences a deceleration, the front
axle normal force during a deceleration event will increase
while the rear axle normal force will decrease by the same
amount. The magnitude of weight transferred from the rear
to the front is a function of deceleration and vehicle
geometry:
WT=(av/g)x(hcg/WB)xWt
=(16.68/9.81)x(0.266/1.465)x23
54.4
=726.8N
Where hcg= the vertical distance from
the CG to ground
WB=Wheel base of vehicle.
The dynamic weight transferred from the rear to the front
must be added to the front axle static weight and subtracted
from the rear axle static weight as follows:
Wfd=Wf+WT
=981+726.8=1707.8N
Wrd=Wr-WT
=1373.4-
726.8=646.6N
Where Wfd=the front axle dynamic vertical force
for a given deceleration.
Wrd=the rear axle dynamic vertical force
for a given deceleration.
% of Weight Front axle Rear axle
Static 41.66% 58.34%
Dynamic 72.5% 27.5%
Pedal Force 378.228 N
Brake Force 2647.6 N
Fluid Pressure 9.28 x 10^6 N/m^2
Braking Torque 310.24 N-m
Deceleration 16.68 m/s^2
Stopping Distance 4.68m
K. Driver safety
We have made the seat and drivers compartment with a fire
resistant material, we have the seat belt of four harness ,
and fire extinguisher of 1 kg with the vehicle and 2 kill
switches –one is in front of the driver and other behind
driver sear. We have rigidly mounted the engine and motor
to the chassis and also taken proper care to avoid any track
to power supply to the chassis. We have also placed a fire
wall which will separate the driver from the power systems
and tractive systems which is made of fire resistant
materials.
Advantages
We have used a 12V dynamo which is directly
connected to the rear shaft(for which the total
power is transmitted) when the vehicle is running
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on either engine or on motor in both cases the
power is generated from the dynamo whose output
was again connected to batteries using a cutoff
circuit. By using this cutoff circuit when the
battery is fully charged, this circuit will
automatically opens
Because of this regenerative system more power is
generated than by using the regenerative braking
that is usually used in the hybrid vehicles.
Because of this the mileage of the vehicle will
increase significantly.
Ecofriendly and fuel economic.
Practically used parts & materials
tires,
hubs,
brake calipers,
tmc ,
tie rods and rear axle of maruti 800, steering rack
we have machined. For suspension we have used
unicorn mono suspension dampers. We have made
the steering column by our own. For tractive
system we have used 48V and 15A supply(4
batteries each of 12V and 15A) and to recharge
the battery while the vehicle is moving on either
of the engine or motor we have used a 12V
dynamo i.e, easily available in the automobile in
market connected to sprocket with maintaining a
ratio of 1:3. For paneling the drivers compartment
and fire wall purpose we have used G.I sheet of
0.4 mm thickness and engine and motor are
rigidly mounted. Drivers compartment is covered
totally with fire resistant material , and also placed
two kill switches for pull and push tires in front of
driver and beside the shoulder of the drivers
compartment.
IV. CONCLUSION
We have tested the kart for its fuel economy under three
conditions running fully on IC engine, running fully on
electric motor, & running on combination of both electric
and ic-engine(hybrid). In our project we have used an old
DC starter motor of a car which has very high current
consumption at start-up because of high torque
requirements during start up,by gaining speed gradually the
current consumption decreases so the battery drains out
quickly reducing the overall efficiency.insead of this to
improve the performance high efficiency DC brushless
motor can be used which has low current consumption.in
cities cars have speed around 40 to 45 kmph and powerful
motor is capable to drive car at this speed due to this
exhaust gases emissions can be reduced in cities and this is
helpful for health and global warming. Currently hybrid
vehicles utilize NI-MH battery technology which needs
replacement after sometime some period. But instead of
this lithium ion batteries which are very reliable can be
utilized.however the intial cost increases this is a new
technology. Nowadays new bio fuels are also made to
reduce the atmospheric pollutionand cut down the fuel
pressures. Also use of CVT in hybrids has proven that they
are having better transmission efficiency than the normal
ones combining CVTs with the smart computer integrated
circuits and smart sensors the efficiency can be greatly
improved. New inventions are lighter but stronger
materials like carbon fibers,HSP are helpful in reducing
overall weight of the car and the small sized high
efficiency engines can be used.
www.wikipedia,org
www.kartbuilding.net
www.howstuffworks.com
