THE PROJECT: The Google Driverless Cars project is being led by Sebastian Thrun, who is also the co-inventor of Googles Street View. Begun in 2010, the self-driving systems are installed in Toyota Prius and Lexus RX for testing. Robo-Taxi, a fleet of technology-driven chauffeur-less cars, is a Google X project. Google X is a secret facility for futuristic technologies such as Google Glass.
HOW IT WORKS: Lidar
On the cars roof is a rotating sensor known as LIDAR (laser radar). It uses lasers to scan up to up to 200 feet in every direction to create a 3D image of the cars surroundings.
A range finder mounted on the rooftop is a Velodyne 64-beam laser which is an obstacle detector and navigator.
A sensor is located on the left rear-wheel that tracks the cars movement and updates its location on a map constantly.
Three in the front and one at the rear determine the distance and position of vehicles and objects in the vicinity.
A camera is fitted to the cars rear-view mirror that helps computers onboard detect, distinguish and recognise moving objects such as other cars, pedestrians and bikers. It also relays traffic-light information to computers.
WHAT IS LIDAR: The Lidar instrument fires rapid pulses of laser light at a surface, some of them at up to 150,000 pulses per second. A sensor on the instrument measures the amount of time each pulse takes to bounce back. Light moves at a constant speed so the LIDAR can calculate the distance between itself and the target with high accuracy. By repeating this in quick succession the instrument builds a complex map of the surface it is measuring. Googles robotic test cars have about $150,000 in equipment including a $70,000 LIDAR system.
ON THE ROAD:
* Testing of driverless cars on public roads has been approved in a few states of the USNevada, Florida and California.
* Nevada issued a licence to a Toyota Prius fitted with experimental technology in 2012.
* The Google project team has a test fleet of about 10 cars. While testing, the team puts a person with an unblemished driving record in the drivers seat and a Google engineer in the passenger seat.
* The car drives at a system preset speed stored on maps and keeps distance from vehicles using sensors.
* As a back up, the system provides an override that allows a human driver