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International Journal of Research In Science & Engineering
Volume: 1 Issue: 3
e-ISSN: 2394-8299
p-ISSN: 2394-8280
Four Wheel Steering-A Review
Abhinav tikley1 ,Mayur khangan2
Abhinav tikley1 ,3rd year mechanical dept,j.d.i.e.t.,yavatmal,abhinavtikley11@gmail.com
Mayur khangan2 ,3rd year mechanical dept, j.d.i.e.t.,yavatmal,mayurkhangan.mk@gmail.com
ABSTRACT
This paper reports on advanced steering system by using rack and pinion mechanism. This steering system
converts the rotational motion into the linear motion to turn the wheels. A 4-wheel steering is completely
different from a 4-wheel drive, in which all 4 wheels are given power rather than to 2 wheels . In this system,
power transferred from front axle to rear axle by using universal coupling through power transfer rod. It
reduces the turning radius as well as the space required for turning. It also enables to change road lane while
driving even at high speed. Quadra system allows for rear wheel to be steered in opposite direction as in front
wheel during low speed and in same direction during high speed. This allows the vehicle to turn in a
significantly smaller radius, sometimes judgmental for large trucks or vehicles with trailers. 4-wheel steering
is a system employed by some vehicles to improve steering response, increase vehicle stability while steering
at high speed and to decrease turning radius at low speed. It also helpful in avoiding skidding as well as
parking problems occurs in metro cities, highways and in rural areas. A 4-wheel steering system is superior
to a 2- wheel steering system. This type of system can be applicable to all types of special utility vehicles. In
most active four-wheel steering systems, the rear wheels are steered by activators and coupling arrangement.
Because of large work load on front wheels and uneven tyre wears of vehicle this system does not getting
popularity.
Keywords : Rack and pinion, 4wheel steering, turning radius, stability, handling.
1. Introduction:
The steering system converts the rotational motion into the linear motion to turn the wheels. The act of guiding
the wheel is called steering.4-wheel steering is a system employed by vehicles to improve stability while
manoeuvring at high speed or to decrease turning radius at low speed. Quadra system allows for rear wheels to
be steered in opposite direction as in front wheels during low speed & in same direction during high speed.
2. History:
From early time, rack and pinion mechanism is used in a steering system of vehicle. For avoiding skidding and
parking problems of vehicles, inventors invented 4-wheel mechanism in 1980’s. Now companies like BMW,
HONDA, MITSUBISHI and NISSAN using 4-ws mechanism.
3. Working of 4 wheel steering:
4 wheel steer steering system works differently during different speed limits. In this system all 4 wheels are
given power rather than to 2 wheels . Operation of this system shows below.
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3.1. Working at low speed:
From 10km/hr to 40km/hr. During this speed, rear wheels moves in opposite direction to the front wheels. It is
useful in turning at residential & parking areas. Turning is easier, as the front wheels move with less steering
wheel motion.
Fig-1: Working at low speed
3.2. Working at medium speed:
At 40km/hr to 80km/hr. During this speed, front wheels takes larger angle than the rear wheels. It is useful in
driving in urban region and major roads. Vehicle moves stably in desired direction with smooth turning.
Fig2: Woking at medium speed
3.3. Working at high speed:
Above 80km/hr. As the speed of vehicle increases, the turning angle of front wheel decreases as well as the
rear wheels in the same direction. In this speed, both front as well rear wheels moves in the same direction.
Fig3: Working at high speed
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4. Calculations for turning radius:
Fig4: Theoretical representation
Where,
R=Turning radius,
L=Wheelbase,
a2 =Distance between centre of gravity and rear axle,
θ=Total inner angle of vehicle,
ϕ =Total outer angle of vehicle,
δ=Total steering angle of vehicle,
Therefore, turning radius of vehicle (R) is,
R2 = a2 2 + L2 (Cot 2 δ),
Where, cotδ = (cosθ + cosϕ) / 2
5. Rack analysis:
Analysis shows stresses acted on the rack. Red color shows maximum stress while blue color shows minimum
stress. Other color shows stresses between maximum and minimum range of stresses. At the ends, maximum
stress obtained while at the middle minimum stress is obtained.
Fig5: Rack analysis
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6. Components used in 4-WH steering system:






Steering wheel
Rack and pinion arrangement
Front axle
Rear axle
Universal coupling
Power transfer rod
Fig6: components of 4 wheel steering system
7. Advantages:
1.
2.
3.
4.
5.
6.
7.
4-ws offer 21% reduction in turning radius.
Stability of vehicle increases.
The vehicle’s straight line stability improved at high speeds.
The negative effect and irregularities of roads are minimised.
The vehicle is less likely to go in spin even driver take a sudden turn.
Conjunction with a rear steer mode 4-wheel steering can significantly improve the vehicle handling at
both high & low speeds.
Due to better handling & easier steering capability driver fatigue can be even over long drive.
8.Disadvantages:
1.
2.
3.
Significantly increase in work load for front tyres.
Large amount of left/right weight transfer seen in 4-wheel steer vehicle.
Uneven tyres wear of front and rear wheel.
9. Applications:
1.
2.
3.
Four wheel steering found its most widespread use in monster trucks.
It is used in farm vehicle.
It is used in ruler as well in metro cities.
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10. Conclusion:
As per the focus of our project we have presented innovative features steering linkage design and its ability to
drive all four wheel using a single actuator. Its successful implementation will allow for developments of 4
wheel steered, power based with maximum manoeuvrability, uncompromised stationary stability, front and rear
tracking and maximum climbing capability.
References:
1.
2.
3.
Sanket bishikar, vatsal gudhka, neel dalal “Design and simulation of 4 wheel steering system”
Dr. kripal singh “Automobile engineering” s tandard public distributor, vol 1, 12th edition, 2012.
ISSN 2274-0149,no.1,jan 2014 “International journal of mechanical engineering & robotics research”
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