Here's a surprising fact: every year, the number of fatalities in Japan, the United Kingdom, and the United States resulting from automobile accidents goes down. Yes, you read that right. There is an actual reduction in the number of people who die in automobile accidents every year.
Unfortunately, car crashes do cause injuries and fatalities , so considering both how widely the use of cars has spread, and the large number of new cars that appear on the market every year, a reduction in fatalities might be somewhat unexpected. But, the figures tell the story. In 1995, Nissan unveiled a bold goal: "By 2015 we will cut the number of people killed or seriously injured in Nissan cars in half." In 2008, this target was first achieved in Europe (United kingdom) which was much earlier than expected. Fatal and serious injuries continue to decrease.
Continuing advances in car safety equipment have helped reach that goal. Most of us know about seat belts and airbags, and advances in other areas, such as crash-absorbing body structures, which further help protect us in the event of an accident. But there are other advances in safety technology that not only help protect us should an accident occur, but actually help prevent an accident from happening in the first place.
Starting in 2005, Nissan unveiled their "Safety Shield" Concept, in an effort to proactively achieve active safety. The idea behind the Safety Shield Concept is that potential approaching risks are categorized into different phases of driving, and the vehicle activates various "barriers" to help provide multiple layers of protection depending on the type of approaching risk. The car is able to help provide prompts to the driver for safe driving depending on the situation, as well as a succession of other safety features as the risk approaches or if a crash should occur. By combining aspects of active and passive safety, Nissan has been able to help reduce the number of fatalities and serious injuries. But just how does Nissan make this Safety Shield Concept a reality? We asked Satoru Yahagi from Nissan's IT and ITS Engineering Department to explain.
Peace of Mind is the First Step Toward Safe Driving
Located on the "Risk has not yet appeared" of the Safety Shield Concept is the "Intelligent Cruise Control" system, a feature that helps facilitate driving in normal "no-threat" conditions. This technology monitors the car's speed and distance from the vehicle directly in front of it and accelerates or brakes the car accordingly, providing automatic cruise control at a speed set by the driver. It automatically maintains space between the car and the other vehicle according to this set speed, making the car cruise at the same pace as the vehicle in front of it. In this manner, this feature helps reduce the driver workload in situations where there is no present danger, helping you to drive with peace of mind.
"Distance Control Assist", like the Intelligent Cruise Control system, is a system located on the very exterior of the Safety Shield Concept. This system helps maintain an appropriate distance to a vehicle directly in front of you by prompting the driver to release the throttle when the driver gets too close to the vehicle ahead..
"If the car draws near to a vehicle ahead while the driver is pressing on the accelerator, the system adds resistance to the pedal and the pedal "pushes back" in order to warn the driver," says Mr.Yahagi. "If the driver then takes his or her foot off the gas, the system applies the brakes. It's different from the Intelligent Cruise Control system in that it works with the driver's operation of the car; you could say it's a system that merges a pleasant driving experience with safety."
Technology to Support Lane Changes
Lane Departure Prevention
On top of features to support "no-threat" conditions, the Safety Shield Concept has additional features to help address situations "where a risk appears" - two examples are the "Lane Departure Warning" and "Lane Departure Prevention" systems.
Lane Departure Warning is a system that warns the driver when the car is on the verge of drifting out of the lane while driving. Lane Departure Prevention is a system that helps support the driver by adding extra controls to help ensure that the car does not drift out of the lane in the first place. Lane Departure Prevention will, for example, apply the brakes on the right-side front and rear tires when the car starts to drift into the left lane, to help the driver return it toward the middle of the lane; this process lets the driver know intuitively that the car is drifting.
Both of these Lane Departure systems use sensor technology that constantly monitors the car's position within the lane as well as its cruising speed. A camera mounted on top of the rear-view mirror focuses on a point about 20m directly in front of the car, keeping track of the car's position relative to the lane.
"The challenge with lane departure technology lies in the fine-tuning of the accuracy," explains Mr.Yahagi. "Since this is a technology that helps provide safety, we need to thoroughly eliminate any errors in recognition. We make selective use of the external information gleaned from the sensors and cameras to help acheive the accuracy for the system. Moving forward, we hope to develop a system that would detect the road lanes even where there are no lane markers. However, in situations in which there are no lanes, in which the road is getting overgrown with grass, or is merely a series of ruts, it can be difficult to tell where the road ends, even with human eyes. We have to define the vague boundaries of such roads. Using this external information to figure out which parts of the road to pay attention to is the key to attaining even more advances in the Lane Departure system."