Nissan debuts next-generation steering
Drive-by-wire will arrive within a year in an Infiniti model
YOKOSUKA, Japan -- Imagine driving down a crowded street when a pedestrian suddenly darts into traffic from behind a parked car.
But before you even have time to react, your car automatically steers around the unsuspecting jaywalker -- all by itself.
This is just one of a host of new products Nissan Motor Co. unveiled Oct. 12 at its annual advanced technology briefing at the company's Oppama proving ground south of Tokyo.
Other upcoming offerings include a steer-by-wire system that will debut in the Infiniti luxury lineup and an active-engine brake system that aims to improve handling and comfort.
The so-called autonomous emergency steering system isn't quite ready for market. But the others will be rolled out in the next two years.
Nissan is embarking on a technology blitz under the mid-term business plan that CEO Carlos Ghosn unveiled last year. The blueprint called for introducing 90 new technologies through the fiscal year that ends March 31, 2016 -- or an average of 15 new features a year.
Nissan bills the steer-by-wire system as the world's first for use in a production vehicle. The concept is similar to the fly-by-wire technology used in jet aircraft.
The system breaks the mechanical link between the driver and the wheels. Instead, it converts steering wheel movements into electronic impulses that control two electric motors moving the front tires.
Nissan says the system has some big benefits.
First, it improves handling by quickening the car's response to the driver's steering input.
It also deadens the bumpy, road-generated vibrations that are transmitted to the steering wheel by a traditional mechanically linked steering system.
That means the driver can keep a lighter touch on the wheel without fear of losing control, even on rough roads.
Moreover, the system teams with a camera-based sensor system to improve on-center driving. Even on crowned roads that slope to the shoulder, the car keeps driving straight without drifting to one side. Less fighting is needed to keep the car on target. All of this lessens driver fatigue and improves safety.
Nissan says it has padded the steer-by-wire system with safety nets to address concern about the driver's loss of direct physical control over the steering.
The possibility of electronic glitches locking up a car's steering has long been an obstacle to adapting drive-by-wire technology in cars.
In Nissan's case, three electronic control units backstop one another to monitor for malfunctions constantly.
If anything goes awry, a failsafe is triggered that -- within milliseconds -- re-establishes a mechanical connection between the cockpit and the concrete, Nissan says.
It does so by releasing a clutch that activates a traditional steering column that normally waits in reserve as a dummy.
The system will debut within a year in an Infiniti model, said Hiroyuki Ashida, an engineer at Nissan's driving control development division. He declined to specify which nameplate will get it.
Nissan's autonomous emergency steering system was perhaps the most dramatic of the new technologies demonstrated in Oppama.
The test car, cruising along a straightaway, suddenly lurches left to avoid a mannequin popping out from the roadside.
The system uses five laser scanners, three millimeter-wave radars and one camera to find potential dangers. Its computers then plot an obstacle free "escape zone" and commandeer the steering to direct the vehicle in that direction.
Nissan has worked on the technology for five years, but it will take another three years before it's ready for market, said Tetsuya Iijima, general manager of electronics engineering.
The biggest hurdles are the complexities of plotting a safe "escape zone" and the need to combine all nine sensors into a smaller, less cumbersome package, he said.
One technology closer to reality is Nissan's new active engine brake. This system, which is compatible with continuously variable transmissions, harnesses the engine's slowing RPMs to help brake the vehicle when the driver's foot lifts from the gas pedal.
The goal is to improve handling and comfort while braking to a stop or slowing to corner. By generating a smoother ride, Nissan says the technology may also eke out fuel economy gains.
Nissan says this low-cost technology will be deployed in the next one or two years and can be used across the lineup in any vehicle that has a CVT. The pulley-type setup of the CVT allows for a smooth engine brake feel that is not as easily replicated by traditional step-geared automatic transmissions.
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