system to automatically detect the presence or absence of objects in a predetermined portion of the space to control, for example, for detecting the busy or free parking spaces in a parking lot

摘要

The system according to the invention, for automatically detectin free and occupied parking spaces (PA) in a car park, comprises A a plurality of probe wave emitters, and B) at least one receiver (10) arranged to capture the reflected waves, returned by reflection of the probe waves from any objects present in the portion of space to be monitored. Each of the emitters is set up to radiate its probe waves with a direction of maximum intensity that is substantially inclined with respect to the direction of maximum intensity of the probe waves emitted by the other emitters (7B, 7C and 7A). Thanks to at least two and preferably three emitters, the system is able to correctly detect the presence of vehicles even if the emitters form a point source situated laterally with respect to the vehicle and not just on the vertical of its centre.