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Discussion Starter · #1 ·
Car and Driver explained the new Steer-By-Wire steering by Nissan/Infiniti that will most likely end up in our Infiniti Q50's, possibly making it the first Infiniti with Steer-By-Wire.

Ton's of benefits to a steering system like this, all explained below. Can't wait to get behind the wheel of an Infiniti Q50 to try it out :)

Steering-Force Sensor
Playing two roles, this unit sends commands to the control modules and acts as the driver's feedback source by varying resistance to the wheel.

Most of the time it's open. Faults in the electronics force it closed, creating a solid mechanical connection between the steering wheel and the rack.

Control Modules
This trio controls the electric-assist motors and the steering-force sensor. They also act as redundancies; you know, for safety.

Steering-Assist Motors
Two of these smaller motors are cheaper than one large one. Plus, this arrangement frees some space for a low-slung longitudinal engine.

So-called “by-wire” controls, which replace a mechanical connection between driver and automobile with an electronic signal, have become commonplace. Electronic throttles are now ubiquitous, braking is increasingly dependent on electronic circuits, and even window switches have become computer controlled. Steering systems haven’t gone completely by-wire for good reason: It’s a little scary to imagine front wheels that may or may not respond to the driver’s inputs, depending on a computer’s whim.

But Nissan’s upcoming steer-by-wire (SBW) system includes a fail-safe clutch in its column. In *normal driving situations, this clutch is disengaged, but if one of the three control modules detects a fault, the clutch snaps shut and the steering acts as a conventional, electrically assisted rack-and-pinion system. The clutch also engages when the engine shuts off, so if one of the first SBW-equipped cars [likely the Infiniti Q50 (pictured below)] fails to start, the owner can still steer the car while pushing it.

Two assist motors mounted at 90 degrees at each end of the rack, plus a steering-force sensor, comprise the SBW’s other components. The steering-force *sensor reports the driver’s desired steering angle to the assist motors by way of the control modules.

Nissan’s stated benefits: Steer-by-wire eliminates steering-system flex and lash, so every driver input yields a direct action at the road. Also—and enthusiasts won’t love this part—SBW completely insulates the driver from road impacts. In a controlled demonstration, we hit a pothole at 30 mph in an SBW-equipped Infiniti G37 test mule. The steering wheel didn’t budge. No wiggle, no shimmy, not even a small jerk. Steering kickback, a common mid-corner occurrence on imperfect pavement, is also eliminated.

A by-wire column can infinitely vary the steering ratio, whereas conventional racks are limited in their variability. Increased safety is another potential benefit. Current stability-control systems yaw the car by slowing individual wheels with brake actuation. Varying the steering angle independently of the steering wheel is another means of stabilizing a slip-sliding car. And a by-wire system could automatically countersteer against a road crown, to make driving, as the Japanese might say, more pleasing to your life force.

While the electronic isolation increases comfort, SBW’s steering feedback redefines artificial, in that it is 100 percent replicated. On-center wander, however, is nil. Remember, electric-assist steering wasn’t all rainbows and lollipops when it rolled out a few years ago. Our December 2012 steering test [“Losing Touch?”] revealed how far electric power steering has advanced in driver satisfaction, and it might take *Nissan a few generations to produce SBW worthy of our approval.

Traffic Keeper

A year or so after Infiniti's steer-by-wire debuts, Volvo will introduce an addition to its electronic safety suite called Traffic Jam Assistance (TJA). In traffic and at speeds below 31 mph, a TJA-equipped Volvo will steer, brake, and accelerate on its own. This is enabled by already existing Volvo safety and convenience features (lane keeper and active cruise control). Switch on TJA, and data from the onboard cameras and radar sensors converges in a master control module, keeping the Volvo in its lane and following the car ahead at a safe distance. The convenience, which we predict will have a 100-percent take rate in Los Angeles, is limited to stop-and-go situations on the highway. So far, TJA can't recognize traffic lights and signs on city streets. Of course, any driver input overrides the system, just as with cruise control.

Electric Feel: Nissan Digitizes Steering, But the Wheel Remains - Feature - Car and Driver

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527 Posts
Agreed. We are getting closer and closer to the point where cars will be like the ones in I, Robot and drive themselves safely at speeds of 100 mph.

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129 Posts
Yeah, I saw this last week.

15 years, people.

That's all it'll take before we'll be able to have affordable cars with automatic driving.
Agreed. We are getting closer and closer to the point where cars will be like the ones in I, Robot and drive themselves safely at speeds of 100 mph.
Too late. Google has had some in production for some time now. They are still in the testing phases, and California has already passed legislation allowing Google to test their cars on public roads.


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5,696 Posts
Yeah, I think everyone knows about the Google car---I think we're all talking about self-driving Infinitis or Fords or Audis that people can buy right off the lot inexpensively that can drive themselves home! :D

15 years is all it'll take IMO..

I mean just 15 years ago, we didn't have any cars with push button start, rear view cameras, lane departure warnings, navigation systems, or blind spot detection. Just imagine what cars will be...15 years from today.

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Steering a Safer Path- Q50 Article from Infiniti:

Steering a Safer Path
First ‘steer-by-wire’ Infiniti Q50 brings car steering into the 21st century
July 10, 2013 – Drivers of Infiniti’s all-new mid-size premium car will be the first to benefit from electronic steer-by-wire technology, inspired by latest jet aircraft technology, when the Q50 hits the roads later in 2013.
Direct Adaptive Steering, standard on certain models in the Q50 range, will for the first time allow drivers behind the wheel to choose how that wheel feels in their hands.
The steer-by-wire technology is a key ingredient in making the Q50 one of the most dynamic and exciting sports saloons on the market – extensively tested by Sebastian Vettel. Infiniti Red Bull Racing’s triple Formula One World Drivers’ Champion – who is also Infiniti’s Director of Performance – helped fine-tune the Q50’s performance and handling at Infiniti’s Tochigi test track in Japan.
Light and smooth for maneuvering, firmer and more agile for sporty driving and challenging roads,
Direct Adaptive Steering makes all options available via simple touch-screen controls. Uniquely in the class, both steering weight and response can be tailored, with all settings stored for each driver in the Q50’s sophisticated memory.
Like a jetliner, Direct Adaptive Steering benefits from several back-up systems – including a conventional mechanical steering linkage.
Direct Adaptive Steering works by electronically transferring the driver’s input to the front wheels where a high-response actuator drives the steering rack. By eliminating the mechanical losses that can dull the responses in conventional systems, steering response is faster and vibration at the steering wheel is eliminated. All this is achieved with a level of feedback from the road that is central to every Infiniti’s performance feel.
Steering is adjusted on a touch screen as part of the Infiniti Drive Mode Selector. Depending on
the model, there are up to four pre-set modes plus a personal setting that allows the driver to mix
and match effort and response to suit individual driving style and type of road.
As a result and in defiance of conventional car steering compromises, the Infiniti Q50 with Direct
Adaptive Steering is as stable and stress-free to steer on a motorway as it is reassuring and
rewarding to handle on a mountain pass – or as light and easy to maneuver in a crowded car park.
A further benefit of Direct Adaptive Steering is that it comes with Infiniti’s latest driving
technology, Active Lane Control. This is unique in using the steering system to keep the car
between motorway lane markings, “magnetizing” the car to within its lane and reducing the need
for continuous steering input owing to crosswinds or minor camber changes in the road surface.
Direct Adaptive Steering comes with triple-mode back-up (three separate electronic control units),
400,000km of real-world test distance behind it and the back-up of the mechanical steering
linkage. In normal use a clutch disengages this mechanical link so it can never corrupt the
steering response.
Direct Adaptive Steering and Active Lane Control will be standard on the Infiniti Q50 3.5 Hybrid
and optional on the 3.7-Liter V6. Infiniti Q50 models without Direct Adaptive Steering are
equipped with electro-hydraulic steering that offers drivers the ability to customize steering
About the Infiniti Q50
The Infiniti Q50 is the newest and most individual entrant in the mid-size premium class to
compete against rivals such as the Audi A4 and BMW 3-Series. Designed to appeal to both the
heart and the head, the Infiniti Q50 marries the brand's flowing, concept-car design themes with a
welcoming cabin inspired by both high technology and traditional craftsmanship. The four-door,
rear- or four-wheel drive luxury sport sedan is available in the Americas with a choice of two highperformance
engines: a 3.7-liter V6 or a 3.5-liter low CO2 Hybrid model.
About Infiniti
Infiniti Motor Company Ltd. is headquartered in Hong Kong with sales operations in approximately
50 countries. The Infiniti brand was launched in 1989. Its range of premium automobiles is
currently built in manufacturing facilities in Japan and the United States. Production in China and
Europe will start soon along with the expansion of the brand’s portfolio.
As the Title Partner and Vehicle Performance Partner of Infiniti Red Bull Racing, Infiniti has a farreaching
technical collaboration with the Formula One team, and Sebastian Vettel, its triple World
Champion driver, serves as Infiniti’s Director of Performance.
More information about Infiniti, its Total Ownership Experience® and its industry leading
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