This document summarizes a project to design and fabricate a cross link four wheel steering system. The project aims to reduce turning radius, improve vehicle handling and stability, and reduce driver workload. It discusses the objectives, literature review, existing steering systems and their drawbacks, the proposed four wheel steering system, its working mechanism, calculations, advantages, disadvantages, applications, and comparisons to two wheel steering. The cross link mechanism connects the front and rear wheels through ball joints and bars to coordinate steering of all four wheels based on driver input.

1. DESIGN AND FABRICATION OF CROSS LINK
FOUR WHEEL STEERING
PROJECT REVIEW
1
13/04/2015DATE
P R O J E C T M E M B E R S :
R . K O U S I K P R A B H U ( 7 2 0 7 1 2 11 4 0 6 8 )
G . PA L PA N D I A N ( 7 2 0 7 1 2 11 4 1 0 3 )
B . P R E M N AT H ( 7 2 0 7 1 2 11 4 111 )
M . R A J A R A M ( 7 2 0 7 1 2 11 4 1 2 2 )
P R O J E C T G U I D E :
M r . C . A . J A G A D I S H M . E ,
A S S I S T A N T P R O F E S S O R

2. STEERING SYSTEM
FUNCTION OF STEERING
• Control of front wheel (sometimes
rear wheel) direction.
• Transmit road feel (slight steering
wheel pull caused by the road surface)
to the drivers hand.
• Maintain correct amount of effort
needed to turn the wheels.
• Absorb most of the shock going to the
steering wheel as the tire hits holes
and bumps in the road.
• Allow for suspension action
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3. OBJECTIVE
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The main objectives for our project
• To reduce turning radius
• To improve handling and stability of vehicle
• To reduce driver work load

4. LITERATURE SURVEY
S.NO TITLE AUTHOR REMARKS
1. Developing quadra steering
system
Manish
k.mistry,jagodanad
ipak
Design and
caculation. stability
in vehicle
2. Developing four wheel
steering system for a car
k.lohith,
s.r shankapal,
Theory for steering,
To provide neutral
steering on vehicle
3. Study of four wheel steering
system to reduce turning
Arun singh,
abhishek kumar
Parts and equipments
required
4. Four wheel steering for
future
Dilip.s.choudhari Quadra steering
system
5. Dynamic characteristics of
multi function four wheel
steering system
I nyoman
sutantra,yusuf
kaelani
Zero side slip
methods
6. Cross link steering system Ashok B.1, Nitish
Singh2, Naman
simple kinematic bar
mechanism
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5. ABOUT EXISTING SYSTEM AND ITS DRAWBACKS
 A steering system is used to change the direction of motion of the vehicle
and to make the vehicle turn either left or right.
 For this purpose, a steering wheel, a steering rod, and a rack and pinion is
connected to the wheels only on the front.
 Thus making only the front wheels to steer.
 The rear wheels remain constant.
 This makes the rear wheels skid when the vehicle turns.
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6. FOUR WHEEL STEERING
 Four-wheel steering (or all wheel steering) is a system employed to improve
steering response.
 Increased vehicle stability while manoeuvring at high speed.
 It also decreases turning radius at low speed.
 By controlling the steering angle of all four wheels, this steering system helps
reduce driver’s steering workload at low speed.
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7. HISTORY OF 4WS
 4WS has its history from the late
1980’s to early 1990’s.
 Honda had four-wheel steering as
an option in their 1987-2000
Prelude.
 Mazda also offered four-wheel
steering on the 626 and MX6 in
1988.
Honda
Prelude
Mazda
MX6
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8. CROSS LINK MECHANISM
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 The material selected for cross bar
and side bar is duplex 2205 stainless
steel hollow pipes of 25.4mm
diameter and 2mm thickness due to
its high tensile strength and its
fracture toughness.
 The setup requires the use of three
ball joints along with a steering rack
and pinion assembly and a modified
knuckle for the attachment of shaft in
the rear end diagonally.
 The material selected for the bar is a
type of super stainless steel having
following properties [2]:
 Ultimate strength = 620 MPa Yield
Strength = 570 MPa Density = 7805
Kg/m3
NOMAL MODE

9. WORKING
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 The setup consists of one cross bar
which runs between front and rear
ends cross ways.
 The bar is joined to the frontier side
of the front knuckle through ball joint
from one end and connected to the
rear side of the rear knuckle with
another ball joint.
 Another kind of bar, side bar (similar
to a toe link) connects the rear two
knuckles.
 All four wheels are linked to each
other, making it a constrained system.
WORKING MODE

10. WORKING
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11. AT LOW SPEED
rear wheels are turned
in opposite direction
of front wheels
 (below 40 miles or 64 kilometers per
hour), in the negative phase, the rear
wheels turn in the opposite direction of
the front wheels ,Reduces turn radius
up to 20 percent , Improves
maneuverability ,Eases parking ,
Simplifies trailer positioning
 At moderate speeds (around 40 miles
or 64 kilometers per hour), the rear
wheels remain straight, or neutral
WORKING MODE
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12. CALCULATION
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• Gross Weight (m) = 1350 kg.
• Weight of vehicle (W) = m * g = 13243.5 N
• Radius of Wheel (r W) =0.3556 m.
• Radius of curvature(R) = 1.7868 m.
• Width of Track(x) = 1.295 m.
• Wheel Base (b) =1.295 m.
• Distance of C.G. vertically above the road surface (h) = 0.55 m.
• Distance of C.G. horizontally from rear wheel axle (l) = 0.963 m.
• Linear velocity (V) = 16 m/s.
• Normal Steer Mode: Radius of curvature(R) = 3 m.
• Cross Steer Mode: Radius of curvature(R)=1.7868 m.
• %Reduction= (3-1.7868/3) * 100 = 40.44 % .

13. ADVANTAGES OF 4WS
 Vehicles move smoothly both in the city and on winding roads.
 Added stability means vehicles can be driven safely.
 Quick and responsive control system will allow gentle steering
operation.
 At high speeds, the four wheel steering system avoids skidding in cars.
 At slow speeds, the four wheel steering system helps in reducing
turning radius by 21% which has its applications in parking.
 The mechanism can be controlled electronically or hydraulically.
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14. DISADVANTAGES OF 4WS
 Complex links to connect front and rear wheels.
 Expensive.
 Additional weight to the vehicle.
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15. RECENT APPLICATIONS
 4ws used in large farm vehicles
and trucks.
 Monster truck.
 Our setup can be applied on the
vehicles which have high
ground clearance ( Lorry, buses
All- terrain vehicles, Sports
utility vehicles) and large
turning radius.
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16. 2WS 4WS
 Only front wheels are steered.
 Turning radius is large.
 Steering response and stability are
less.
 Less complicated.
 More complicate for lane change.
 Both front and rear wheels are
steered.
 Turning radius is smaller than
2WS.
 Steering response and stability are
high.
 More complicated.
 Easily taking lane change
COMPARISON
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17. COMPARISION
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18. REFERENCE
 [1] PACEJKA, H. B. 2006. Tyre Mechanics and Vehicle Dynamics,
Butterworth-Heinemann .
 [2] Bansal, R.K. 2010. A textbook of Strength of Materials, Laxmi
Publications.
 [3] REIMPELL, J. 2001. The Automotive Chassis - Engineering
Principles, Butterworth-Heinemann .
 [4] William F. Milliken, Douglas L. Milliken, 1995. Race Car Vehicle
Dynamics , Society of Automotive Engineers
 [5] Swanson Analysis Systems, Inc. ANSYS software (Version 14.0).
 [6] Dassault Systèmes SolidWorks Corp., a subsidiary of Dassault
Systèmes, S. A. (Vélizy, France) Solidworks software
(December9,2009), version 4.
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