Vanamala, U. and koganti, R., "An Innovative Design Concept of Four Wheel Steering Mechanism for an Automobile," SAE Technical Paper 2013-01-2845, 2013, doi:10.4271/2013-01-2845.
The main characteristic of vehicle moving on road is related to its response to the drivers command and to environmental factors affecting the direction of motion of vehicle. The two basic problems in handling the vehicle are control of vehicle along the desired path and stabilization of the direction of motion of vehicle against external disturbances. The vehicle with best handling characteristics is the vehicle which can always be controlled by the driver.While parking the vehicle and doing sharp turnings the vehicle with two wheel steering cannot be more significant. The two wheel steering system takes large radius of turning and requires more space to take turn. Hence four wheel steering is preferable than two wheel steering systems. A multi-function four wheel steering system could improve directional stability at high speeds, sharp turning performance at low speeds, and parking performance of a vehicle.Generally there are three types of steering systems which include front wheel, rear wheel and four wheels. The paper deals with the mechanical steering system which can perform all these operations. The paper presents a new design of steering system which involves a connector, coupler and bevel gears.In a front wheel steering, only front wheels steer, and in a rear wheel steering only rear wheels will steer to get turning. In a four wheel steering system at low speeds, the front wheels and rear wheels are out of phase for low turning radius. However at high speeds, the front and rear wheels should be in phase to increase the stability of a vehicle. The paper presents a single steering mechanism arrangement offering three modes of steering operations possible which can be selected by the driver.