23-08-2012, 04:51 PM
FOUR WHEEL STEERING SYSTEM
1FOUR WHEEL.ppt (Size: 455 KB / Downloads: 69)
INTRODUCTION
Four-wheel steering (or all wheel steering) 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.
Steering is the term applied to the collection of components, linkages, etc. which will allow for a vessel (ship, boat) or vehicle (car) to follow the desired course. An exception is the case of rail transport by which rail tracks combined together with railroad switches provide the steering function.
OBJECTIVES OF OUR PROJECT
Minimum stopping distance: The vehicle should stop within a minimum distance and should avoid skidding also.
Sensitivity: The sensitivity of a brake to changes in the friction coefficient at the rubbing surfaces should be minimum.
Size and Weight: The weight of the disc of the braking system should be kept at minimum. Moreover the size of the parts of the braking system should be such so as to get accommodated in the available space.
Design Simplicity: It should be very easy to replace the friction pads when required. Moreover these should be very small number of parts to wear or not function properly.
Incompressibility of the actuating fluid:
In the case of hydraulic brakes a fluid under pressure is used to transfer force or motion. Increasing the pressure will compress the fluid into a smaller volume. This should be prevented by using more of liquids than gases or altogether preventing the use of both.
PRINCIPLE
At high speeds, the four wheel steering system avoids skidding in cars taking higher n sharper turns using ABS system.
And at slow speeds, the four wheel steering system helps in reducing turning radius by 21% which has its applications in parking etc.
For parking and low-speed maneuvers, the rear Wheel steer in the opposite direction of the front wheels, allowing much sharper turns.
ADVANTAGE
(1) Computer-controlled Quadra steer can be switched on and off and has an effective trailer towing mode.
(2) A computer determines how much and in which direction the rear wheels should move, and whether the rear wheels should turn the same direction as the front wheels or in the opposite direction. The movement is variable up to a couple of inches.
CONCLUSIONS
The aim of 4WS system is a better stability during overtaking maneuvers, reduction of vehicle oscillation around its vertical axis, reduced sensibility to lateral wind, neutral behavior during cornering, etc., i.e. improvement of active safety.
1FOUR WHEEL.ppt (Size: 455 KB / Downloads: 69)
INTRODUCTION
Four-wheel steering (or all wheel steering) 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.
Steering is the term applied to the collection of components, linkages, etc. which will allow for a vessel (ship, boat) or vehicle (car) to follow the desired course. An exception is the case of rail transport by which rail tracks combined together with railroad switches provide the steering function.
OBJECTIVES OF OUR PROJECT
Minimum stopping distance: The vehicle should stop within a minimum distance and should avoid skidding also.
Sensitivity: The sensitivity of a brake to changes in the friction coefficient at the rubbing surfaces should be minimum.
Size and Weight: The weight of the disc of the braking system should be kept at minimum. Moreover the size of the parts of the braking system should be such so as to get accommodated in the available space.
Design Simplicity: It should be very easy to replace the friction pads when required. Moreover these should be very small number of parts to wear or not function properly.
Incompressibility of the actuating fluid:
In the case of hydraulic brakes a fluid under pressure is used to transfer force or motion. Increasing the pressure will compress the fluid into a smaller volume. This should be prevented by using more of liquids than gases or altogether preventing the use of both.
PRINCIPLE
At high speeds, the four wheel steering system avoids skidding in cars taking higher n sharper turns using ABS system.
And at slow speeds, the four wheel steering system helps in reducing turning radius by 21% which has its applications in parking etc.
For parking and low-speed maneuvers, the rear Wheel steer in the opposite direction of the front wheels, allowing much sharper turns.
ADVANTAGE
(1) Computer-controlled Quadra steer can be switched on and off and has an effective trailer towing mode.
(2) A computer determines how much and in which direction the rear wheels should move, and whether the rear wheels should turn the same direction as the front wheels or in the opposite direction. The movement is variable up to a couple of inches.
CONCLUSIONS
The aim of 4WS system is a better stability during overtaking maneuvers, reduction of vehicle oscillation around its vertical axis, reduced sensibility to lateral wind, neutral behavior during cornering, etc., i.e. improvement of active safety.