Google is building a patent portfolio in driverless car technology. In December, the US Patent Office awarded Patent 8078349 for transitioning a car from human-driven to autonomous mode. A key problem which this patent solves is to ensure that the car knows its precise location when switching into autonomous mode. GPS may not be precise enough for the vehicle to understand where it is (it may only be accurate by 10 meters) and to determine the direction it should take. Therefore Google proposes using markings called landing strips – which may be embedded in the road. The human driver stops the car on a landing strip which the car then detects and uses to determine its location. Landing strips may even contain an embedded QR-code. But landing strips need not be marked on the ground. They may consist of recognizable well defined locations which a car can detect by examining its surroundings and for which it can look up the data in a database or online. An example could be a conventional, clearly marked parking spot.
The patent also addresses additional issues of providing instructions to the autonomous car when switching to autonomous mode. This could include instructions to move to a different location where the car is needed or to proceed to a service station for maintenance.