Electric power steering

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As mentioned in the piece about the new hybrid Jazz, this car has electric power steering.  About eight years ago, I made the prediction that “European cars, because of their smaller sizes and lighter weight have utilized electric steering sooner than across the Atlantic, but I expect electric power steering will replace traditional hydraulic power steering units within the next five to seven model years.”  It now seems that I was right when I looked into my crystal ball.  (Unfortunately, it does not give out lottery numbers!)

Since hydraulically activated power steering has been around since 1951 when the Chrysler Crown Imperial was the first car offered with the new concept, we should have got it right by now.  And we have got it right, to the point that we have developed another system which uses less energy than hydraulic pumps, and in today’s energy conscious environment, less energy used is savings at the petrol pumps.

Today’s systems use electronics and electrics and has dispensed totally with the hydraulics.  This was first seen in the Honda NSX sports car and Honda again introduced the system on the S2000 sports car.  Smaller, lighter electric units are also used on Honda’s Hybrid Insight sedan (petrol saving, of course).  And the Jazz!

However, Honda was not the lone pioneer here, as Saturn used electric power steering on the Vue SUV and the Ion sedan.  GM’s 2004 Malibu used Delphi’s new E*STEER unit.  Dephi’s system was also used in the 2000 Fiat Punto and Volkswagen’s 2001 Lupo 3L TDI.  Other OEM vendors of electric power steering systems are Visteon with EPAS used in the MGF and ZF Freidrichshafen AG with ZF Servolectric.

As opposed to electric power steering, four-wheel steer has also been around for a while, but these have been mechanical systems.  Honda offered it on the Prelude but dropped it later, and more recently it was offered on the full-size GM pickups and SUVs.  For large vehicles like a pickup truck, this reduced the turning circle from something akin to that of a sea-going oil tanker to that of a small car.  However, these mechanical systems were expensive and physically complex.

Four-wheel steering systems of the 1980s were in essence, essentially mechanical, with the wheels linked at pre-determined angles to make up for a vehicle’s tendency to understeer.  Towards the end of the 1990s, manufacturers such as Nissan were beginning to develop solutions based on electrically and even hydraulically-operated actuators to take the dynamic performance of their vehicles forward.  Electronic control of rear wheel steering has enabled handling to be fine-tuned even further, notably in the case of rear-wheel drive vehicles.

Auto engineers know there are many advantages with electric/electronic systems in automobiles, and one significant savings lies where electrical and electronic components actually replace conventional mechanical and electromechanical components.  Such is the case with electric power assisted steering systems, steer-by-wire, and active steering systems, including electro-hydraulic power steering, magnetic power steering, intelligent steering systems, active rear-steer systems, four-wheel steering systems, steer-by-wire, and multi-axle steering systems.  This is a complex area of engineering that covers active, passive, and semi-active suspension systems, electromagnetics, damper suspension, digital suspension control, and vibration and handling control systems.

These advances have been acknowledged, but complexity and cost has stopped them becoming universally adopted, but as electronic systems become more sophisticated and costs become more affordable, many of these advancements are now becoming available in mid-range production automobiles.