Distance Control Assistance is available on the 2009 Infiniti FX. Click image to enlarge
By Jim Kerr
Once a year, members of the Automobile Journalists Association of Canada (AJAC) meet near Niagara-on-the-Lake, Ontario to test the new vehicles seen on Canadian roads. Out of that testing, votes are tabulated for the Best New Car of the Year and the Best New Utility Vehicle of the Year.
This is also an opportunity for the vehicle manufacturers to showcase their new technologies and vie for Best New Technology and Best New Green Technology awards, sponsored by Shell Canada.
This year, a panel of technologically savvy journalists (gearheads in some circles) were overwhelmed by eleven new technologies: four in the Green Technology group and seven in the New Technology group. As a member of this jury for the past several years, I have never had a more difficult time deciding which ones should receive my votes for the best technologies.
This week, let’s begin with one new technology presented by Infiniti called Distance Control Assist (DCA). DCA evolved from Nissan’s research into driver behaviour. This system is part of Nissan’s safety strategy that provides a “Safety Shield” around the vehicle. Anything that intrudes into that area is a potential threat to occupant safety. Nissan’s research showed that many drivers follow too closely the vehicle in front of them. This can occur due to inexperience, inattention, or simply the fast pace of society and our seemingly constant urge to get somewhere quickly. The results can be disastrous.
The Distance Control System uses a three-fold approach to help keep the driver at a safe distance behind other traffic. The system provides a tactile warning through the accelerator pedal, and visual and audible warnings are also given if the driver doesn’t respond. There are cruise systems on the market that will keep the vehicle at a driver preset distance behind another vehicle, but DCA is totally separate from any cruise control system.
The system uses laser range finding to detect another vehicle ahead. The computer uses the vehicle speed, distance to the vehicle ahead and closing speed between the two vehicles to calculate if there is a threat present. Visual warnings begin at approximately 120 metres but no action is required. If a “risk” situation is detected, the first step is to prompt the driver to take their foot off the accelerator pedal: a computer controls a motor in the accelerator pedal assembly that pushes back against the driver’s foot. The driver senses this instantly but can still override it if necessary.
If the driver releases the accelerator pedal, the system will apply the brakes if the closing rate between the two vehicles is still determined to be a “risk”. The brakes can be applied up to about .25 G, which isn’t a panic brake but it will slow the vehicle noticeably. Compared to a full ABS stop, this automatic braking would be about one-third to one-half the braking effort. If the vehicle ahead is slowing to a stop, the brakes will continue to be applied until your vehicle is also stopped. In many situations, the driver would want to apply the brakes themselves. Stepping on the brake pedal, the driver can fully apply the brakes. Changing lanes so there is no vehicle ahead will allow the automatic braking to stop, as will turning off the system.
If the driver ignores the “risk” of a vehicle ahead, increased feedback pressure on the accelerator pedal is accompanied by a warning light on the dash and an audible chime.
Nissan research has shown that by providing tactile feedback through the accelerator pedal, driver response time to release the pedal has been reduced. Audible warnings alone produced an average .32 second response time, while the tactile pedal feedback warning lowered this average response to just .24 seconds. It may not sound like much difference, but it can be the difference between safe driving and a collision. The system is currently available in the Infiniti FX models.
On another note, Nissan has used the computer controlled pedal technology to test a prototype “ECO Pedal”. This system uses the same tactile pedal feedback to modify driver behavior to optimize fuel economy based on vehicle operating conditions. Along with “Eco” lights on the dash, the pedal feedback can improve fuel economy by five to 10 per cent. A system like this would help all drivers, but I can see it especially useful to novice drivers, who may not have the experience to sense how the vehicle is operating.