Nissan's Advanced Technologies Safety Innovations

Safety: moral imperative and top R&D priority

"Each year, more than 1.2 million people die on the world's roads," says Toshimi Yamanoi, Nissan's general manager of Global Safety. "The World Health Organization says, traffic accidents were already the tenth most frequent cause of human fatality in 2008, and by 2030, they are expected to be number five. For any automaker, safety should be the number-one priority. It's an absolute moral imperative: we must do all we can to help reduce motor-vehicle-related deaths and injuries."

That's why safety is at the very top of Nissan's long-term R&D agenda. And why Nissan safety specialists have a wide mandate to impose changes on any vehicle program across the lineup.

"At Nissan we have taken up the challenge and we're determined to lead the global industry in safety. If you look at our safety pipeline, I hope you will conclude that's not an idle boast," Yamanoi says.

First priority for Nissan engineers is to focus on what they can control: helping to reduce deaths and injuries involving Nissan and Infiniti brand vehicles.

"The starting point is to gather as much data as we can," Yamanoi says. "When a Nissan is involved in a serious crash, we try to analyze what happened. Our R&D centers around the world monitor local developments and we travel overseas frequently to see the situation first-hand."

This determined approach has already achieved impressive results. A 1995 initiative to halve the number of fatalities in developed markets involving Nissan vehicles by 2015 achieved its goal six years ahead of schedule. But the safety team is not resting on its laurels.

"Our goal is ambitious," Yamanoi says. "We want to reduce deaths involving our vehicles to 'substantially zero.' Is zero too ambitious? Maybe so - but to set our sights on anything less would be to say that some deaths are acceptable. No death should be acceptable."

To meet this ambitious goal, Nissan's safety agenda has widened from protecting vehicle occupants to proactively detecting risks and reacting to help prevent accidents before they occur - or in Nissan's terminology, "Advanced Crash Avoidance Technology."

This is at the core of Nissan's Safety Shield initiative: a long-term effort to zero-in on every identifiable risk factor and develop remedies to help prevent accidents and reduce fatalities, particularly among pedestrians.

Here's the challenge. Until now, detecting risk has been entirely the driver's responsibility. How can the next step be taken, giving cars the ability to detect risk, evaluate it and automatically execute the correct response to the circumstances?

Matching biology at sensing risk

"In the previous age of mobility, highly-evolved sensory ability was standard equipment," says Tetsuya Iijima, a senior Nissan safety specialist. "I'm talking about horses. Their senses of hearing and smell are much more acute than ours. And they have an amazing field of vision that extends to almost 360 degrees.

"Horses also have a keen sense of self-preservation. So if you order a horse to gallop over a cliff, he will quite sensibly refuse. Cars have had none of that ability to detect and judge risk."

Iijima's colleague Yamanoi interjects with another lesson from nature. "Look at how a school of fish or a flock of birds can change direction in an instant, very sharply but without a single collision. Why can't vehicle traffic do the same?"

The answer, until now, has been that humanity lacked the technological capability.

"Successive revolutions in electronics and IT have opened a whole new frontier in safety," Iijima says emphatically. "Advances in areas like video signal-processing have given us a new set of tools. Plus, the hardware needed to deploy new features - chips, sensors, miniature cameras and the like - is now very affordable.

"So our challenge boils down to replicating biological functions with the new electronic capabilities at our disposal. And sensing is by far the most difficult task."

"To understand how tough it is, consider what happens when a ball bounces into the road in front of a car," Yamanoi adds. "An automated system can easily spot the object. But only a human will instantly think to look for the child who threw the ball.

"We have a long way to go, but if you look at the technologies starting to emerge I think you'll agree that we are progressing quickly."

All-round perspective


The use of advanced electronics to enhance the driver's ability to perceive risks comes under the heading of Intelligent Transportation System (ITS) technology.

The "intelligence" involved in ITS is often as much a matter of engineering insight as technological function. At least that was the case when Nissan engineers approached a universal problem from a fresh perspective.

First commercialized in the early 1990s, backup video cameras have become commonplace as the massive proliferation of mobile-phone cameras has slashed the price of equipment. It's a useful feature, but the perspective offered by conventional backup cameras is less than ideal.

Nissan engineers looked at the issue from a different angle and decided: "We need a bird's-eye perspective that shows the vehicle from above in the context of surrounding objects."

This insight spurred the development of Nissan's world-first, award-winning Around View Monitor (AVM). The very first time you try to maneuver in a tight space you will see why AVM goes light years beyond conventional backup cameras.

This fall, Nissan engineers are planning a significant next step to help make parking lots safer by using the four-camera AVM system to add "Moving Object Detection", an innovative function that helps overcome the risk of pedal misapplication.

In Japan, about 7,000 accidents occur each year, typically in parking lots, when a driver hits the accelerator instead of the brake or steps on the accelerator too hard, thus causing a collision.

The AVM team identified a way to help overcome this risk by using video signal data from the system's four cameras to make the car "context aware" - in other words, able to tell the difference between an expressway and a parking lot.

With this new function, the car will still accelerate smartly when you "floor it" on the freeway. But try the same thing in a parking lot and the car will refuse to comply - which is precisely what a horse would do if you tried to spur it into a brick wall. It's a matter of simple "horse sense."

For Nissan's engineers, though, AVM was just the first step in a concerted effort to realize the full safety potential of video.

One camera, three huge strides in safety

Beyond simply using the backup camera's video signal to display moving images on a monitor, Nissan engineers were intrigued by the potential for advanced signal-processing to interpret objects and patterns in the car's vicinity.

From the video signal, they learned how to:

  • reliably identify traffic lane parameters;
  • identify other vehicles as they entered the driver's blind spot; and
  • detect the movement of objects in the car's vicinity - for example, a pedestrian entering the car's path as it reverses.

"This was very, very exciting for us," says Tetsuya Iijima, Nissan's senior manager of ITS technology, "because we could see the path to solving several safety issues with a single rear-mounted camera. This way, we can compensate for humankind's evolutionary failure to match the functionality of the horse."

With one eye on each side of its head, the horse has remarkable 360-degree vision that allows it to detect danger approaching from behind. By contrast, our peripheral vision spans just 180 degrees. And our three-dimensional perception is even narrower: 140 degrees. While driving, we need to keep all the visual power we've got focused on the road ahead.

Nissan engineers used this equine analogy in framing the question: How can we give drivers eyes in the back of their heads?

1. Blind Spot Warning
As they change lanes, drivers sometimes fail to notice other vehicles in the notorious "blind spot," the area adjacent to the rear side of the car that doesn't show up in mirrors.

Nissan's Blind Spot Warning (BSW) function helps reduce the risk of collision by displaying a warning light whenever the rear camera detects another vehicle in the blind spot zone.

2. Lane Departure Warning
Cars stray from the traffic lane for all sorts of reasons. Drivers often get distracted - perhaps reaching for coffee or tuning the radio. Usually, the driver realizes the error and corrects course in a split second with no consequences. But in far too many instances, lane-departure errors have fatal consequences. In fact, they are involved in more than half of all fatal crashes in North America and Europe.

Nissan's Lane Departure Warning (LDW) function helps reduce the risk with visual and audible warnings whenever a driver begins to stray from the lane without signaling.

"We are talking about more than 20,000 deaths a year here," Iijima says. "Obviously, if we can support the driver with functionality that addresses lane-departure errors we should be able to help save a great many lives.

3. Moving Object Detection
Whenever a car reverses, unseen pedestrians and other moving objects entering its path pose a "back-over accident" risk.

A 2006 U.S. government study estimated that back-over accidents kill nearly 200 people and injure more than 7,000 people each year.


Nissan's Moving Object Detection (MOD) function aims to help reduce the likelihood of such accidents. When the car goes into reverse, the MOD signal-processing unit scans the image stream from the rear camera in search of moving objects that match the patterns of identified risks, alerting the driver when a moving object is detected.

All three coming soon
These three ITS safety innovations - Blind Spot Warning, Lane Departure Warning and Moving Object Detection - will soon be offered in a wide range of Nissan products.


From Predicting Forward Collisions…
In heavy traffic, slowdowns move like waves across many kilometers as the tail lights on each vehicle alert the following car to brake. It's a fragile and haphazard information relay that all too often fails.

When just one distracted driver in a chain of 1,000 cars fails to heed the brake-light signal of the vehicle ahead in time, the result is often a rear-end collision, or a chain of collisions. Even when there is no crash, the haphazard transfer of information leads to jerky, inefficient traffic flow.

For decades, automotive engineers have sought a way to overcome this inelegant, inefficient and dangerous traffic protocol. Nissan engineers now believe they have a viable answer.

The root of the issue is that the signal to brake (provided by the brake lights of the car in front) leaves the trailing driver only a split-second to see and register the information before reacting.

So Nissan engineers asked: "How can we help warn the driver earlier, giving him more time to react? And how can we reliably obtain the necessary advance information?"

The answer: identify when the vehicle two cars ahead starts to brake.

The most elegant solution would be to glean this data from a forward video camera, as this would add one more function to Nissan's growing menu of advanced video safety features, at very low cost. Unfortunately, though, a video camera can't see through the car in front.

"What does work, as we discovered, is to use a simple, front-mounted radar device," says Tetsuya Iijima, Nissan's senior manager of ITS technology. "From this data stream, we can reliably detect evidence of braking two cars ahead. The result is Nissan's Predictive Forward Collision Warning function that gives the driver a critical few seconds of extra time to react."

…to helping prevent forward collisions
Giving drivers early warning when cars ahead begin to brake is certainly a useful step. But when cars ahead suddenly screech to a halt, Nissan engineers realized the need to go one step further - intervening automatically to help avert a collision.

"With Nissan's Forward Collision Avoidance System we have taken safety technology into new territory," Iijima says. "Until now, we have followed the principle that safety aids should support the driver's natural powers via enhanced vision, earlier awareness of risk, quicker reaction time and protection from injury should the worst occur.

"This is the first time that Nissan has empowered a car to take action without specific instruction from the driver. And so the key question was: 'At what point should the car take on this role?'"

In a forward collision (a rear-ender from the opposite perspective) every micro-second is crucial. As every additional kilometer of differential speed between colliding vehicles increases the risk of death or injury, the time it takes for a driver's foot to move from accelerator to brake can make a life-or-death difference.

"After a lot of study," Ijima says, "we concluded that it is crucial not to intervene while the driver still has a chance to swerve rather than brake. Because of that, we had to carefully program the system to brake automatically - and with emergency force - only once a collision was absolutely inevitable.

"In terms of interpreting human behavior, modeling crash physics and applying multiple technologies, this is as sophisticated as it gets in automotive safety engineering," Iijima says.


Surviving the worst-case scenario

No matter how many safety precautions you build into a car, the worst-case scenario - impact - can never be completely eliminated. But when the worst happens there is still much we can do to help make the impact survivable.

"We have made huge strides over three decades since I started my career in safety," says Yamanoi, a veteran at 56. "Before joining Nissan I had dinner with a friend who'd lost a colleague in a crash. And he begged me: 'Please, make a balloon that will inflate around a car to protect people inside. Or invent some sort of magnetic force field to keep cars from colliding.'

"We haven't figured out how to make a force field yet, but today's airbags are pretty close to what my friend asked for - except that it's inside the car, not outside.

"One by one, over the years we've greatly helped to reduce death and injury from almost every type of accident: front, side, rear and rollover. Seatbelts and airbags have made a huge difference, and so has the ability to design front ends that can absorb the impact of a crash.

"But what really helped us move forward was the ability to simulate every aspect of a crash: what happens to the car and to passengers. In the early days I had to go to accident scenes, which was emotionally hard. And it was also tough to decipher what had actually happened. We were able to crash many test cars, too. But we didn't always get answers to our questions.

"The first big breakthrough in safety research was the crash dummy - which GM introduced about 1965. Our insights grew as dummies became more and more sophisticated.

"But the big leap came with the ability to simulate events electronically. Now we can understand even the tiniest details with the help of supercomputers. And we can give the same rigorous treatment to every variant of every model in the lineup."

Yamanoi is pleased, perhaps even amazed, by the progress he's witnessed and helped achieve over three decades. But he is far from satisfied.

"The issue used to be fatalities and injuries inside cars. There is always more to do, but we've come a long way towards resolving that issue. But in a sense that was the easy part because those people are inside our structures. Now we're at the point where pedestrians account for a substantial portion of all traffic fatalities in Japan. It is pedestrians who are most at risk - and they are a lot harder to protect.

"Beyond Japan, pedestrians account for too many of the deaths in emerging markets where fatalities continue to rise at alarming rates. We feel a tremendous sense of urgency about this.

"Many of the big questions for the future in crash safety focus on the front end of the car - because it's the front that usually hits pedestrians.

"Until now, the front end has been territory more or less equally shared by Powertrain, Design and Safety. Powertrain requires lots of room for the engine. Design uses the front to give the car character, a bold face. And Safety needs the front end as an impact buffer zone.

"This equation is changing as engines get smaller and lighter - they don't need as much space. With EVs, the motors may even disappear inside the wheel hubs. But Safety still needs space up front to buffer impact - at very least 300 to 400 millimeters. And if we are to help protect pedestrians, Safety must have the decisive voice in shaping the front end.

"So in future, front-end shape and size will remain first and foremost a function of crash safety."

Lights On for Life

Most traffic injuries and fatalities are anything but random. Again and again, they occur for the same tragic reasons, in the same places - and at the same times of day.

By far the most likely time for accidents is at dusk, when rush hour coincides with sunset.

As the sun slips below the horizon, light conditions deteriorate faster than drivers can adjust their eyes. At the same time, roads are packed with tired commuters and pedestrians abound. This is a recipe for disaster that repeats itself daily.

Traffic safety specialists can clearly measure the effect by correlating later summer sunsets with lower death tolls.

Dawn poses similar risks, but as light is increasing, and as pedestrians are less abundant, the effect is less deadly.

To help counteract this risk, many nations north and south of the tropics set clocks ahead one hour in summer months to ensure more people are home safe by sunset. Another approach, adopted by Canada and, more recently, the European Union, is mandatory "Daytime Running Lights" (DRLs) that stay on all the time.

In Japan, where clocks do not change in summer and DRLs are not street legal, a fresh approach was needed to counteract alarmingly high pedestrian deaths and injuries at dusk.

The team behind Nissan's Auto Headlight started with the observation that most drivers did not turn headlights on until dark - well after safety dictated they should. Either they didn't realize that twilight is the most dangerous time, or they simply forgot.

So the team set out to automate the task of turning headlights on and off. The basic function was not too difficult to achieve as light-sensitive switches are by now a commodity item.

The challenge was to ensure the headlights don't flick on and off every time the car passes under a shady tree - but to ensure they do work in tunnels. That required the team to come up with logical software able to distinguish when the lights are needed.

The other hurdle was rainy days. Although headlights are a good idea in the rain, light levels can vary widely when it's raining. But the workaround for this was simple. When you turn on the wipers, the headlights come on, too.

Auto Headlight will soon be available on all new Nissan models in Japan, and introduced gradually in other markets.


Interior safety advances

In recent decades, seatbelts, airbags, headrests and other safety features have greatly helped to enhance safety inside the passenger compartment. But as Nissan engineers seek new ways to help keep vehicle occupants safer, many of the remaining issues relate to human behavior.

As the old traffic safety slogan goes, "Seatbelts Save Lives." But only if people use them. Although not wearing a seatbelt makes death in a crash 13 times more likely, seven percent of Japanese and 17 percent of Americans still do not buckle up.

Using a wide variety of tactics from safety campaigns to warning buzzers, governments and automakers have worked painstakingly to increase seatbelt usage.

Nissan's latest effort to help eliminate every excuse for not buckling up is a seatbelt that's easier to fasten and more comfortable to wear.

The "Low Friction Seatbelt" features a belt woven with an innovative herringbone pattern that slides through the mechanism with less friction - helping to make it much easier to pull round the body and fasten. Once buckled in, enhanced pliability reduces the discomfort some people feel when wearing conventional seatbelts.

The ultimate goal: global leadership in safety

"Ultimately, we want Nissan and Infiniti to be known around the world as the foremost brands for safety, Yamanoi says. "And we believe we are in a good position to achieve that goal.

"We know that future strides in safety will hinge on a combination of deep insight into human behavior and the creative application of technology - particularly in electronics. As we're strong in all these fields, and we're motivated, there is no reason why we can't succeed.

"Still, it is human insight that will help us overcome the real challenge: reducing deaths and injury in the emerging markets. As most customers in these nations can't afford expensive equipment, on one hand we have to look for smart, low-tech solutions. On the other hand we have to make technology more affordable. But watch us, we'll do it!"

 

 

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Issued by Nissan