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General Motors vehicle to vehicle (V2V) technology


General Motors Corp. has built a fleet of Cadillacs that have a sixth sense, so to speak; they combine aspects of other technologies (like “smart” cruise control), at a lower cost:

  • When an imminent rear-end collision is sensed, the car in front (to be crashed into) flashes its brake lights and reverse lights to grab the attention of the oncoming car...
  • ...while the oncoming car's driver sees a green car in the V2V display, then a yellow one, then a red one with a seat-buzz warning; and then the brakes slam on automatically, not so hard as to cause injury, but firmly enough to come to a stop and prevent injury or damage.
  • When you’re about to change lanes (as indicated by using your turn signal), if there’s anyone in your blind spot, an icon appears in your side mirror, and your seat buzzes
  • When you’re about to change lanes, if there’s someone coming up fast from the lane you’re going into, an icon appears in your side mirror, and your seat buzzes

GM said there were well over 800,000 “blind-spot” accidents each year; this would eventually prevent most of them.

The projection now is that GM will produce a full line of cars with this technology, from Aveo to Caddy, at an optional charge of about $200. Not only will GM share the technology with other companies (at a price), as it did with OnStar, but it is working with other companies to set standards, so that other automakers can use the same basic technologies with completely different equipment. Donald Grimm, senior researcher at GM, said that aftermarket kits were likely as well, a possibility because the system will allow for both active and passive transponders. An active transponder uses GPS to figure out where it is, and connects into Stabilitrak (or the vehicle’s other stability control system) to figure out speed and braking, and communicates both to any vehicle within 300 yards.

How the vehicle to vehicle (V2V) system works

Using vehicle-to-vehicle (V2V) communication, a vehicle can detect the position and movement of other vehicles up to a quarter of a mile away. Vehicles will be equipped with a simple antenna, a computer chip, and GPS (Global Positioning System) technology; they will know where the other vehicles are by communicating directly with them, and other vehicles will know where they are -- in blind spots, stopped on the highway but hidden from view around a blind corner or blocked by other vehicles. The vehicles can anticipate and react to changing driving situations and then instantly warn the drivers with chimes, visual icons and seat vibrations. If the driver doesn’t respond to the alerts, the car can bring itself to a safe stop, avoiding a collision.

The system would replace the long range scanning sensor for adaptive cruise control, forward vision sensors for object detection, mid-range blind spot detection sensors, and long-range lane change assist sensors. GM has the ability to replace all of these sensors with one advisory sensor that will provide all-around, instantaneous traffic intelligence. This promises a better and significantly less costly way of sensing other vehicles around your car while driving.

During a demonstration attended by acarplace in March 2007, GM showed scenarios in which V2V technology can assist drivers. Using V2V communication, the vehicle alerts the driver to vehicles in blind spots with a steady amber light in the side mirror. If the turn signal is activated, a flashing amber light and gentle seat vibration on the side notifies the driver of a potentially dangerous situation. The vibration was enough to get our attention but not a sudden distraction - it was much more subtle than our pager.

Pile-ups on congested roads during rush hour due to a chain reaction rear-end collisions could be lessened. Using V2V, the vehicle monitors messages from other vehicles up to a quarter of a mile ahead. The trailing vehicle warns the driver first with visual icons and seat vibrations on the front and then automatically brakes if there is danger of a read-end collision with the vehicle ahead.

In addition, GM’s V2V technology can warn the driver when vehicles ahead, regardless of lane, are stopped or traveling much slower or any vehicle ahead brakes hard, allowing the driver to brake or change lanes as needed. It also can use rear lights to warn the other driver when the approaching vehicle is moving very quickly and a rear-end collision is imminent.
While other vehicle manufacturers are developing similar technology, GM’s unique advantage is in its ability to leverage or enhance existing systems such as OnStar and StabiliTrak systems to deliver this solution more quickly and cost effectively.
“GM is the world leader in Telematics,” said Patrick Popp, director of GM’s Advanced Technical Work in Safety. “Our V2V technology builds on GM’s earlier Telematics systems to give our customers new meaningful traffic safety and efficiency applications.”

Aftermarket and vintage-car implications

A single sensor is used for location, speed, direction, and braking activity. According to GM, the system’s antenna should be placed as high up as possible, preferably on the roof; as currently configured, it needs to have access to signals from several GPS satellites. Again, however, an aftermarket system could be devised with an antenna installed on the roof, trunk, or perhaps even temporarily on the edge of the dashboard or the package shelf, for vintage cars which owners are loathe to drill holes into (or which are going to be shown and can’t have 21st century technology clearly showing). This “passive” aftermarket unit could be used to show the vehicle position if not its braking activity, speed, and direction, and presumably the automatic braking and warnings would work in the oncoming vehicle (though the automatic activation of reverse and brake lights would not work if the “passive” vehicle was stopped).

Since standards would be used for the technology, enterprising aftermarket makers might even design a system that lets owners splice into the brake light wires to provide that data (if that’s allowed in the final standards for passive systems).

A stability control system is currently required for the full active system to work; vehicles without stability control will get the active system. GM is currently considering making the transmitters standard in every car, and charging only for the full system.

Vehicle to infrastructure technology

GM is working with government officials to develop test road infrastructure in Michigan. In theory, dangerous intersections could be made safer by using small transponders under the road surface to warn cars to slow down, or to tell the status of the traffic light from a distance away; traffic could be made smoother by having all traffic lights give "warnings" or status reports to the vehicle telematics. This is all being built into the standards for the system.

User safety issues

The impact of the radio waves - in roughly the 5 GHz wavelength - on people has not been forgotten by GM, according to Donald Grimm. He noted that they were thinking of how frequently the system’s radio pulses needed to be, to reduce exposure, and whether vehicle occupants would need shielding. While GM has not yet done studies on the impact of exposure to the wavelength, it is used by newer wireless computer communications systems, and at some point a lab is likely to test the effects of exposure.

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