NARROW TILTING OF CAR
Published on: Mar 3, 2016
Transcripts - NARROW TILTING OF CAR
Under the Guidance of
Mr. Amol Talankar
Author : Sagar k. Rajput
Mechanical VIII Sem.
Narrow track cars are without doubt the future of urban mobility. These
cars have a very short wheel track in comparison to normal cars. Most of
the international car companies have production models and prototype of
narrow track cars. Some examples are Nissan Land Glider, Nissan Pivo,
Honda 3R-C, etc.
Such cars are mostly single seated or double seater with back to back
seating configuration. These cars have several advantages:
•Half the width means half the weight, more rigidity, more access to
narrow roads, easier parking and much quicker transit times.
•In an electric vehicle, the lighter weight of this much smaller vehicle will
help to enhance torque power characteristics of an electric motor to
achieve “linear acceleration”.
•At highway cruising speeds, such cars will be using half the frontal area
and half the drag co efficient, plus reduced running losses make for a very
energy efficient vehicle.
All these advantages make the narrow track vehicle so appealing as an
alternative to the car.
Such cars combine the comfort of a car with the functionality of a motor
bike. But these cars have a very important and dangerous drawback. With
a very comparatively narrow track and heights almost equal to normal
cars, these cars are very susceptible to rolling. As of now all such narrow
track cars are electrically driven and have a limited top speed and hence
this drawback is comparatively negligible. But sooner or later these cars
will have to get highway cruising speeds. Then this drawback will be of
Our project took shape as an attempt to face this drawback. We thought
so if the cars has the functionality of a motor cycle why not give it the
flexibility of a motor cycle. This gave use to the idea of an auto-tilting car.
There has been many tilting body designs in rail but what we have done is
not just a body tilting, in it the car tilts as a whole. Recently there had
been some development in making
three- wheeled tilting cars like the carver, but only prototypes or concepts
exist in the field of four-wheeled tilters.
‘Narrow track cars’ is not a new term. Several production models do exist and several
prototypes are being tried out by major automobile companies.
Some production models are Nissan Pivo, Honda 3R-C etc
Several automobile majors like Toyota, Mercedes, Nissan, Kia, Suzuki etc have prototypes
for narrow track cars.
A very successful product is a narrow car of the name NARRO.
This car is expensive at $46000, but has managed to find
customers which stresses the acceptability of narrow cars for
This car is powered by two motors each driving one rear wheel. It has a
maximum speed of 120 kmph. But narro is a tall car, too tall for its track. It
rolls tremendously on curves, the manufacturer have compensated for this
by providing it a very stiff suspension. Since the car is only meant for
urban road use the compromise made in suspension does minimum
damage, but even with stiff suspension, the threshold velocity of this car in
a curve is very low in comparison to a full track width car.
Tilting trains are today common in Europe and Japan. These trains are
rail-running, they have very high curve velocities. Inorder to enable trains,
to negotiate curves at high speeds, tracks are slightly banked (upto 11
degrees). But these trains are too fast, and it is not possible to tilt track
beyond a limit because trains also pass along these curves really slowly
Tilting trains are an optimum solution for this problem. These types of
train, tilts the body on the curve, this in a sort enables faster curve
threshold speed and increased passenger comfort. The figure below
shows two tilting mechanisms used in trains.
THREE WHEELED TILTING CARS
These type of cars are a new species, but their number is fast
increasing. These cars tilt about their rear wheels. Either there can be
two wheels at the rear like the carver. Which has two wheels at the rear
and the car body tilts about the rear wheels. Steering is done using front
Or these can be one wheel at the rear about which the body tilts. Like the
GTR (Grand Tilting Racer).
The objective of this project work is to successfully
develop a design of a tilting mechanism for a narrow
tilting car. The mechanism is to be reliable, simple, cost-
effective and practically feasible. The aim of this tilting
mechanism is to provide banking to the car on unbanked
curves, so as to enable added threshold speed on curves
in comparison to a narrow non-tilting car. This system is
also supposed to enhance passenger comfort as the side
force felt by passengers in a car taking a turn is
comparatively less in a tilting car. Also in our purpose is
the fabrication of a mini-prototype –a remote controlled
toy car-to demonstrate the tilting in real world.
FABRICATION AND DESIGN PROCEDURE
The frame has been designed with parameters taken from an already
existing and successful narrow track car. The entire suspension system
has been redesigned and an additional tilting tyre holder was welded on
the frame both at front and rear. The adoption of an already existing
frame for our design ruled out the requirement of stress analysis. The
frame is sure to hold on, even in case of most hostile conditions, as it is
a tried and tested design.
DESIGN OF DRIVE MOTOR.
In the design of the car we have followed a “no risk policy”, instead of designing
all the parts by ourself. We have used parts already tried and tested in others
cars. This is advocated as we needn’t have to test these already tested parts
unnecessarily. Also these parts are already in use and are satisfactory in their
operation. The only new design is actually the suspension and the tilting
mechanism. In design we have decided to stick to an electrical drive system for
the vehicle, though it is going to be more expensive than oil, it is certainly
futuristic and eco-friendly. Besides, the electrical drive system can be mounted
lower and can help to lower the center of gravity and thus increase the threshold
speed at curves
DESIGN OF THE TILTING MECHANISM
The tilting mechanism design was a complex question. Initially it was decided
to use power screw driven screw driven screw holders for each individual
wheel controlled by a stepper motor. The design almost completed. It had
•Each wheel could be moved independent of the other.
•More precise control was possible with power screw lifters.
3)It could be modified to incorporate other systems like body level control, ground
clearance adjustment system et
LITHIUM ION BATTERY
A lithium-ion battery (sometimes Li-ion battery or LIB) is a family of
rechargeable battery types in which lithium ions move from the negative
electrode to the positive electrode during discharge, and back when charging.
Lithium-ion batteries are common in consumer electronics. They are one of the
most popular types of rechargeable battery for portable electronics, with one of
the best energy densities, no memory effect, and a slow loss of charge when not
in use. Beyond consumer electronics, LIBs are also growing in popularity for
military, electric vehicle, and aerospace applications. Research is yielding a
stream of improvements to traditional LIB technology, focusing on energy
density, durability, cost, and intrinsic safety.
STEPPER MOTOR DESIGN
For tilting the vehicle by 20 degree each side should be able to move up and
down by at least 13 cms .
This gives the total rotational measure for the stepper motor i.e. 64.13 degree in all.
The stepper motor is to be controlled by a microprocessor based on inputs from the
following types of sensors.
•Speed of sensor
•Steering position sensor
•Yaw rate sensor
A stepper motor (or step motor) is a brushless, synchronous electric motor that can divide a
full rotation into a large number of steps.
TESTING OF DESIGN
The designed tilting mechanism has been recreated and tested in pro-e
simulation program. Initially, the tyre resisted movement and after many
rounds of fine-tuning the dimensions, the assembly began to show
positive results. Only the rear rotating tyre had to be tested as the front
was not under powered motion. The front rotating tyre assembly was
also dimensionally modified to suite the rear one. Certain range of
motion was imparted to the rear rotating tyre and the process was
captured as a video for presentation. The complete frame design with
final dimensions is:
Several of the advantages of our design over conventional
car was discussed previously. They are summarized below:
•This car is much more efficient than a conventional gasoline car
due to reduced aerodynamic drag at cruising speed due to reduced
•This design combines the utility of a car with the flexibility of
•Narrow track cars are definitely future of urban mobility, but our
tilting car can also handle highway cruising as well.
•Like any other electric car, it is cheap to run and environment
•It is also likely to be a solution to real day traffic congestion.
1.The car design in itself is futuristic and can be soon find in some
production versions of four-wheeled tilting cars.
2. A feature can be added to the existing suspension using a minor
programming change, the system can also act as body leveler in
transverse direction using the level sensor, this feature enables added
gradability in sideward direction.
1) Salim Maakaroun, Wasima Khali GEOMETRIC
MODEL OF A NARROW TILTING CAR USING
2) Gohl J, Rajamani R Development of a novel tilting
controlled narrow commuter vehicl(internal
report May 2006)
3) pro-E design