Robots Compete At DARPA Grand Challenge
Driverless vehicles raced at the tracks of DARPA.
So how were they operated?
Lidar a laser scanner used for light detection and ranging were the sensors commonly used there.
A beam of light bouncing off a spinning mirror lights the terrain ahead. Then the sensor calculates the distance of objects by measuring the time taken for the beams to return. Line by line, the robot also builds up a simple 3-D model of the terrain in front of the vehicle. For a clearer picture several laser scanners are used.
But laser scanners have limitations: Seeing only a narrow slice of the world with a relatively short range (60 to 150 feet) it cannot tell colors and may bounce off shiny surfaces. Diffucult to spot certain hazards (such as a body of water). They're also bad for stealthy applications, such as those preferred by the military, because they emit light.
