Electric power steering has taken a long time, but the technology behind it has been around for a very long time. Actually, power steering was about as long as a car, and large trucks were fitted with aftermarket systems as early as 1903, but it was not offered as an OEM option until the 1950s.
This technology is ubiquitous today thanks to its inclusion as standard equipment on virtually all new cars and trucks, but it remained optional on a number of lower-priced entry-level vehicles through the 1980s and 1990s.
What is power steering for?
The purpose of power steering is to reduce the amount of effort the driver needs to steer. This has traditionally been achieved with hydraulic power, which can be generated by a belt-driven pump that turns a motor. However, the technology has undergone a constant stream of innovation and upgrades since it first appeared as an OEM option in the 1950s.
The first major upgrade to traditional hydraulic steering that saw widespread adoption was electro-hydraulic steering. This early form of electric power steering added further assistance to traditional power steering with electric pumps.
This technology has been largely superseded by electronic power steering, which eliminates hydraulics entirely. Electric power steering is available in a wide range of vehicles from almost all manufacturers.
A closely related technology known as control-by-wire is an important component in moving towards a fully wired cars.
Electro-hydraulic power steering
Electro-hydraulic power steering (EHPS) is a hybrid technology that works in the same way as traditional hydraulic power steering. Like traditional systems, it uses hydraulic power to reduce the force needed to drive the car.
The difference between the two technologies lies in how hydraulic pressure is generated. Where traditional systems pressurize with a belt-driven pump, electro-hydraulic power steering systems use electric pumps.
One of the main advantages of electro-hydraulic power steering is that the electric pump does not necessarily lose power when the engine is off. This is a great safety feature as it makes it easier to manage if the engine dies while driving on the road.
This feature has also been useful in electric vehicles and some fuel-efficient gas vehicles because it can provide power steering for vehicles that don’t have a traditional gas or diesel engine and hybrid vehicles that are designed to cut gas. engine at highway speeds.
electric power steering
Unlike hydraulic and electro-hydraulic systems, electric power steering (EPS) does not use any form of hydraulic pressure to provide steering control. The technology is fully electronic, so it uses an electric motor mounted on a steering gear or rack to provide direct assistance.
Because there is no power loss in generating and transmitting hydraulic power, these systems are generally more efficient than hydraulic or electro-hydraulic steering.
Depending on the specific EPS system, the electric motor can be mounted either on the steering column, directly on the steering gear, or on the steering rack.
The sensors are used to determine the required steering force and then applied in such a way that the driver needs to apply the minimum amount of effort to turn the wheel.
Some systems have discrete settings that determine the amount of steering assistance provided, while others operate on a variable curve.
Most manufacturers offer electric power steering on one or more of their models.
What is a wired connection?
Electric power steering systems remove the hydraulic component while retaining the traditional tie rod, but true steering systems have done away with the tie rod.
These systems use electric motors to turn the wheels, sensors to determine how much steering effort, and steering feel emulators to provide tactile feedback to the driver.
Control-by-wire technology has long been used in certain heavy equipment, forklifts, wheel loaders and other similar applications, but it is still relatively new to the automotive world.