SUBMITTED TO :-
Dr. Ashish Sharma
BRAJ MOHAN TOMAR
Prof. C.S. Koli
• Four wheel steering is a system that allows the
rear wheels to turn for maneuvering, rather
than just follow the front wheels.
• It is a system employed by some vehicles to
improve steering response, increase vehicle
stability while maneuvering at high speed, or
to decrease turning radius at low speed.
Controling rear wheels
• At slow speeds, the rear
wheels are turned in
the opposite direction
of the front wheels. This
can lessen the turning
radius by approximately
rear wheels are turned
in opposite direction
of front wheels
• At faster speeds on the
highway, the rear
wheels are turned in
the same direction as
the front wheels. This
improves lane changing
maneuverability and is
for vehicles towing a
all four wheels
are turned in
• The mechanical 4WS uses two separate
steering gears to control the front and rear
• The hydraulic 4WS uses a two-way hydraulic
cylinder to turn both the wheels in the same
direction. It is not possible to turn them in the
• The electro/hydraulic 4WS combine computer
electronic controls with hydraulics to make
the system sensitive to both steering angle
and road speeds
• a vehicle requires less driver input for any
steering As with two-wheel steer vehicles, tire
grip holds the four wheels on the road. when the
driver turns the wheel slightly, all four wheels
react to the steering input, causing slip angles to
form at all four wheels.
• The entire vehicle moves in one direction rather
than the rear half attempting to catch up to the
• There is also less sway when the wheels are
turned back to a straight-ahead position. The
vehicle responds more quickly to steering input
because rear wheel lag is eliminated.
MerMitos:bility in crowded environment
safety in driving / parking
The Chinese University of Hong Kong
it has got cornering capability, steering response, line stability, lane changing and low-speed maneuverability.
• , 4WS is complex and expensive. Currently the vehicle with four wheel steering is more than vehicle with the conventional two wheel steering.
• it is growing in popularity and it is likely to and more new vehicles.
• As the systems become more commonplace four wheel steering will drop.