Design and Fabrication of Four Wheel Steering System

Abstract

The cars that are designed in the industry tend to under steer or over steer. A car cannot automatically compensate for these problems, if this would have been the case ,the driver would enjoy neutral steering under different operating condition. With the help of 4 wheel steering system the automobile design engineers, would provide near neutral steering. In situations like low speed cornering, vehicle cornering and driving in heavy traffic, due to vehicles large wheel base, driving would not be feasible which gives rise to a requirement of the mechanism that reduces turning radius. This can be achieved by using 4 wheel steering mechanism, instead of the regular steering system. Fourwheel steering system is an effort on the part of automobile design engineers that aim to provide near-neutral steering. In situations like low speed cornering, parallel parking, driving in city conditions with heavy traffic. In tight spaces, driving would be difficult due to the larger vehicular wheelbase. Hence a mechanism is required which results in less turning radius. It can be achieved by implementing four wheel steering mechanism instead of the traditional regular two-wheel steering. The main aim of this project is to implement this system. In a 4 wheel steering system the rear wheels do not turn in a direction of the curve on the road and thus hamper the efficiency of the system. This system is not a preferred choice because the conventional mechanical Four wheel steering system is quite complex. However, a few cars like Honda Prelude, Nissan Skyline GT-R have been equipped with 4 wheel steering system in which the rear wheels are turned by an angle in order to help the front wheels in steering. 3 modes interchangeable 4-wheel steering is a modification of the present steering system. It is used for vehicular handling and it also assists the driver by controlling the steering angle, which makes the parking and handling easier in congested area. For meeting this application, the rear wheel would either steer in the same or in the opposite direction as the front wheel. This allows the reduction in the turning radius of the vehicle when sliding to the sideways. Our basic requirement of the project is to transmit the motion given on the steering wheels to the rear wheels to control it like the front wheels. After studying the actual design of the Four wheel steering mechanism, we have found that this system increases the efficiency of the traditional driving system. It makes the steering system more useful than it has ever been. We will even achieve greater vehicular stability and controllability. The steering will be quicker and easier as compared to the systems we have been using now.