The evolution and application of rear steering

By Ryan


In common sense, most of cars around us use front-wheel steering, however,car manufactures have been tried to use other ways to enhance the cars’performance and rewrite the traditional acknowledge to automobiles.

  Generally there are two types of Actuation forms: the front drive and rear drive. Both using front-wheel steering but have different disadvantages: The front drive will usually have the problem of understeer (As the picture on the left shows); the rear drive is more flexible, but still can cause oversteer (As the picture below shows).

  To overcome these problems, engineers have developed rear steering systems to assist front-wheel steering. Due to scientific and technological progress, there comes two types of real steering: Passive rear wheel steering and Active rear wheel steering.

  

 Many modern vehicles have passive rear steering, the passive steering system uses the lateral forces generated in a turn (through suspension geometry) and the bushings to correct this tendency and steer the wheels slightly to the inside/outside of the corner. This improves the stability of the car, through the turn. This effect is called compliance understeer/oversteer and it, or its opposite, is present on all suspensions.

Active rear wheel steering, in some ways has been part of  four-wheel steering systems, the rear wheels are steered by a computer and actuators. The rear wheels will make turning with small angle by the command from ECU and computer, thereby lower the effects of under steer and decrease the chances of spinning by diverting part of the G-forces generated in a turn from the front to the rear tires. At low speeds the turning circle can be tightened so parking and maneuvering is easier.

Since the first car has born in 1886, car industry experience great progress, rear steering is only a small part of the history of automobile technology revolution, With no doubt, the evolution of steering will never stop, and the future of this field would be more brilliant. 

Sources

http://www.autohome.com.cn/tech/201111/260594.html

Steering - Wikipedia, the free encyclopedia

Images

http://www1.m.autoimg.cn/zx/newspic/2015/1/13/640x0_1_q30_2015011311241774514.jpg

http://baike.baidu.com/pic/%E5%90%8E%E8%BD%AE%E8%BD%AC%E5%90%91/8207500/0/aec379310a55b31972a0eac146a98226cffc172c?fr=lemma&ct=single

http://baike.baidu.com/pic/%E5%90%8E%E8%BD%AE%E8%BD%AC%E5%90%91/8207500/0/a8ec8a13632762d03dcccc0ba5ec08fa503dc690?fr=lemma&ct=single