The article includes:
- the BMW’s front and rear bumpers, two laser scanners and three radar sensors sweep the road before and behind for anything within about 200 meters. Embedded at the top of the windshield and rear window are cameras that track the road markings and detect road signs. Near each side mirror are wide-angle laser scanners, each with almost 180 degrees of vision, that watch the road left and right. Four ultrasonic sensors above the wheels monitor the area close to the car. Finally, a differential Global Positioning System receiver, which combines signals from ground-based stations with those from satellites, knows where the car is, to within a few centimeters of the closest lane marking.
- An important challenge with a system that drives all by itself, but only some of the time, is that it must be able to predict when it may be about to fail, to give the driver enough time to take over. This ability is limited by the range of a car’s sensors and by the inherent difficulty of predicting the outcome of a complex situation
- much of the technology that has helped autonomous cars deal with complex urban environments in research projects—some of which is used in Google’s cars today—may never be cheap or compact enough to be employed in commercially available vehicles. This includes not just the LIDAR but also an inertial navigation system, which provides precise positioning information by monitoring the vehicle’s own movement and combining the resulting data with differential GPS and a highly accurate digital map