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This article is presented by:
MOHD.ZAFAR
MEHANICAL ENGINEER
G.T.B.K.I.E.T
CHHAPIANWALI MALOUT(PUNJAB)
PIN NO. 152107
Steer-by-wire – a solution to many design challenges
INTRODUCTION
Despite recent setbacks, the steer-by-wire technology is alive and well – at least in specific off-highway markets. In this realm, many X-by-wire solutions are already in production and could easily be adopted by the passenger car industry. The article provides an overview over technologies, standards and players.
In a regular steering system as we know it today in vehicles and working machines, the steering device usually consists of a steering wheel, a steering actuator, a physical page link between the steering device and the actuator, and a power source. To improve active and passive safety and comfort for the driver, and for economic reasons, the industry has been working on ways to eliminate the mechanical connection between the steering device and the wheels and replace it by a purely electric or electronic solution. Steer-by-wire is a feature that promises to make such a solution possible. By approving regulation ECE R79 Revision, the UN Economic Division for Europe (UNECE) covered the use of full steer-by-wire systems on roads without mechanical backup.
Steer-by-wire is an advanced steering technique for adaptable steering and modularity which eliminates the need for a mechanical connection between the steering device and the steering wheel. With steer-by-wire, the connection is purely electric or electronic. Actuators steer the wheels and also give feedback to the driver. In today's driving world, a steering column between the steering device and the wheels is the standard.
It all started with the EU-funded X-by-Wire project with seven industrial partners from the automotive industry and two universities in 1996. Over the years, several prototypes have been built. They show impressively that steer-by-wire offers a long list of advantages such as additional comfort functions and simplification of the production process to its users as well as extensive design freedom. Steer-by-wire also has a positive impact on the environment – since no hydraulic pump is needed, no hydraulic fluids need to be disposed of and energy consumption can be optimized.
Steer-by-wire offers numerous advantages, such as selectable steering characteristics, reduction of noise and vibration from hydraulic parts, the fact that the steering unit may be placed where needed, making the driver seat position variable, and – important for designers and manufacturers – the simplification of assembly and the possibility of new modular design concepts.
The implementation of steer-by-wire in vehicles faces technical, legal and regulatory issues, and it has to be accepted by the user, that is, the driver, as a safe method of navigating a vehicle. The design of the future steering system must meet the functional and safety requirements of all authorities involved. Another major challenge is to keep the costs of steer-by-wire systems driving on public roads at a reasonable level. In order to handle these issues, several companies formed a working group within the TTA-Group, the Steer-by-Wire Working Group. One of the goals of the Steer-by-Wire Working Group is to define a reference architecture that shows that steer-by-wire is not more expensive than conventional steering systems. The challenge is to combine safety, low cost, and modularity.
