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Visual Processing

The processing system revealed to be properly dimensioned for the automatic driving of the vehicle. Moreover, current technology provides processing systems with characteristics definitely more powerful than the one installed on ARGO: a commercial PC with a 200 MHz Pentium processor and 32 Megabytes of memory.

On such a system, enhanced by a video frame grabber able to acquire simultaneously 2 stereo images (with 768 x 576 pixel resolution), the GOLD system processes up to 25 pairs of stereo frames per second and provides the control signals for autonomous steering every 40 ms. Obviously the processing speed influences the maximum vehicle speed: the higher the processing speed, the higher the maximum vehicle speed.

The approach, based on the Inverse Perspective Mapping (IPM) transform, has the only drawback that the movements of the vehicle (pitch and roll) do not allow to detect reliably the obstacles at distances higher than 50 meters; on the other hand, since the tour involved driving on highways, during the trip the assumption of flat-road (required by the IPM transform) was always met. Anyway, it is under study an enhancement to the IPM transform that allows to get rid of the flat-road assumption and therefore to handle also generic roads.

During the whole tour the system processed about 1.500.000 images (each with size 768 x 288 pixel) totalling about 330 Gigabyte (330.000.000.000 bytes) of data.