A DRIVER steering a car on a twisting road has two distinct tasks: to match the road curvature, and to keep a proper distance from the lane edges. Both are achieved by turning the steering wheel, but it is not clear which part or parts of the road ahead supply the visual information needed, or how it is used. Current models of the behaviour of real drivers1,2 or 'co-driver' simulators3–5 vary greatly in their implementation of these tasks, but all agree that successful steering requires the driver to monitor the angular deviation of the road from the vehicle's present heading at some 'preview' distance ahead, typically about 1 s into the future. Eye movement recordings generally support this view6–9. Here we have used a simple road simulator, in which only certain parts of the road are displayed, to show that at moderate to high speeds accurate driving requires that both a distant and a near region of the road are visible. The former is used to estimate road curvature and the latter to provide position-in-lane feedback. At lower speeds only the near region is necessary. These results support a two-stage model1 of driver behaviour.
Why do some cars respond so well to the driver? Great handling makes you feel safe and in control – and makes panic swerves and steering corrections as effective as possible. The lightest touch of the wheel should direct the steering system effortlessly and precisely. As well as a well-designed suspension parts, it takes a good quality steering system and steering parts to achieve excellent handling. If you’d like to know the anatomy of a steering system and how it supports handling, road holding and driveability, here is an easy overview.
The function of a steering parts
When you rotate the steering wheel, the car responds. But how does this steering system in cars give you a smooth route forward? A group of parts called the steering system transmits the movement of the steering wheel down the steering shaft to move the wheels left and right – although car wheels don’t turn at the same angle.
The popular rack and pinion steering system
In most cars, small trucks and SUVs on the road today, there is a rack and pinion steering system. This converts the rotational motion of the steering wheel into the linear motion that turns the wheels and guides your path. The system involves a circular gear (the steering pinion) which locks teeth on a bar (the rack). It also transforms big rotations of the steering wheel into small, accurate turns of the wheels, giving a solid and direct feel to the steering.
How does power steering affect the rack and pinion?
It’s likely that if you drive today, you’re used to power steering. Contemporary cars, and especially trucks and utility vehicles have a power steering system function – also called power-assisted steering. This gives that extra energy (either hydraulic or electric) to help turn the wheels and means parking and manoeuvering requires less effort than with simple manual force. The rack and pinion steering system is slightly different with power steering, with an added engine-driven pump or electric motor to aid the steering assembly.
So is ease the only benefit of power steering? The system allows you to have higher gear steering and means you have to turn the steering wheel less to turn the wheels further (less steering wheel turns lock-to-lock). It therefore sharpens up response times and makes the steering even more precise. With such busy roads and traffic jams, this means drivers can more safely manoeuvre in close proximity to other vehicles. Keeping tight control at all speeds, in any conditions and in critical situations, will help to avoid accidents.
What are the components of the steering system in cars?
Whatever a car’s make and model, quality auto steering parts support a flawless drive. Premium rack and pinion parts manufactured by MOOG include axial rods, tie rod ends, drag links, centre arms, steering rack gaiter kits, tie rod assemblies and wheel end bearings.
These steering parts are robust and hard wearing enough to provide both strength and durability. Choosing parts which meet OE manufacturer specifications means the whole assembly will be responsive and long-lasting.