Electric power steering is taking control

By Nicole DiGiose

Because it's gradually replacing traditional hydraulic steering, electric power steering (EPS) is likely to become mainstream within the automotive industry in the near future.

Ahead of the curve

EPS assists in the effort of steering a car that uses mechanical linkage. Through the use of an electric motor directly coupled to either the steering gear or steering column, EPS offers more assistance than hydraulic power steering. Sensors are used to detect the motion and torque of the steering gear or column, and a computer module applies assistive power via the electric motor.

Electric power steering diagram. Image via  mouser.com .

A turn for the better

Not only does EPS provide directional control and improve car handling for the driver, it also slightly increases fuel efficiency due to a reduction in parasitic losses. Because there is no belt-driven hydraulic pump constantly running fluid, EPS systems have an advantage when it comes to protecting the environment and saving money. More drivers are moving to EPS because eliminating an engine-driven hydraulic pump increases gas mileage by about one MPG. EPS steering systems are more economical to run, and as they're lighter and more compact than hydraulic systems, they're easier to package and install. 

Depending on driving modes and the model of the car (sport, luxury, etc.), designs can even be software-modified. Because it's cheaper to manufacture EPS than traditional hydraulic systems, a back-up mechanical linkage such as rack and pinion steering is common.

Electic power steering system. Image via caradvice.com.

By incorporating electronic stability control, electric power steering systems can aid drivers in corrective maneuvers, as well as in saving money and bettering the environment. These days, EPS systems are becoming more and more common. In the coming years, they're predicted to be the standard steering system in most vehicles.

For more information on EPS, or to view a product list of EPS parts, including charge pumps, DC/DC convertors, position sensors and power switches, visit Mouser’s EPS applications page.