Designing of Four Wheel Steering System depending on vehicle speed

Project Abstract / Summary : In a typical front wheel steering system the rear wheels do not turn in the direction of the curve. This curbs on the efficiency of the steering. In order to avoid this, a 4 wheel steering system has been a preferred choice due to improved controls in low speed as well as high speed driving. Based on the equation researched by Sano and et.al, the rear wheels moves both out of phase to the front wheels under a certain speed, as well as in phase when the vehicle reaches cruise speed. This helps the driver in low speed cornering and city parking conditions, and also increases vehicle stability in high speed lane change maneuvers. The most interesting thing in my project is that it is completely mechanical, i.e. no electronic actuators or electronic control module has been used. I have made a cam follower mechanism which will generate a ratio of the front steering angle to the rear steering angle based on vehicle speed. This ratio is the input to a Continuously Variable Transmission (which in this case operates in low speed because it divides the steering input only). The CVT finally gives the steering angle to the rear wheels based on driver's input. Although avoiding electronic instruments will decrease the efficiency of the system by a few points, but the design has been so made that it is easy to maintain, low cost and hence perfect for the Indian market.

Why did you choose to work on this project topic : According to a report published in Dailymail.co.uk, the number of vehicles registered in New Delhi in 2011 was 4.76 lakhs. With the ever increasing vehicle density in our country, low speed cornering, parking in tight spaces and driving in city conditions has become very difficult. In order to ease the situation for a driver, 4 wheel steering system is an excellent solution. It can not only decrease the turning radius considerably but also increases vehicle stability, thus making driving safe and comfortable.

Project Category : Mechanical / Automobile / Aeronautical
------------------------------------------------------
Institute/College Name: Asansol Engineering College
City: Asansol
State: West Bengal
Participating Team From: Third Year