STEER-BY-WIRE CONTROL SYSTEM

STEER-BY-WIRE CONTROL SYSTEM

ABSTRACT

There is a visible trend in the automobile industry for an increasing number of electronic systems in vehicles directly responsible for active and passive driving support. These applications will greatly increase overall vehicle handling and safety by assisting the driver in critical situations.
In steer by wire systems, the costly hydraulically assisted mechanical packages that actuate and assist steering are replaced by electronic and electrical packages. Electronic and optical data buses replace the bundles of wires that sit behind the instrument panel. However, for implementing this system the following systems have to be developed first.
At the moment, a radical change in steering technology becomes evident all over the world. The long lasting obvious dominance of hydraulic systems in passenger vehicles is now seriously being questioned. More and more automakers are planning to use electronically controlled steering systems for the next vehicle generation. By 2005 in Western Europe, presumably 40 – 50 % of new vehicles will go into series production equipped with such a system.
There are multiple reasons for electrically controlled steering systems in passenger cars, since both environmental and financial advantages are obvious.
One of the main issues is fuel economy, along with a reduction of toxic emission, due to use of electrical steering. In a conventional hydraulic system, the permanent oil rotation results in mechanical and hydraulic friction losses. According to the distance traveled, a medium sized vehicle will have a share of approximately 0.3 – 0.4 additional liters per 100 Km fuel consumption. Apart from a minute, negligible standby current electrical energy from the on board system only when mechanical steering work has to be done.
Use of the respective hydraulic pumps, nowadays relevant for any engine variant can be dropped, such as belt, oil-reservoir and pipe arrangements.