Method for detecting presence inside a locked vehicle and associated detection device

A method for detecting presence inside a locked vehicle, by a detecting device comprising at least one internal ultra-wideband transceiver module able to transmit toward inside the vehicle and at least two external ultra-wideband transceiver modules able to transmit toward outside the vehicle, said method comprising:

• a) detection of locking of the vehicle;
• b) for a first predetermined period of time, alternation of transmission by the internal module of waves at various predetermined frequencies and at various associated predetermined powers, and simultaneous transmission of waves by a first external module,
• c) reception, by said internal module, of reflected waves,
• d) reception, by a second external module, of waves transmitted by said first external module,
• e) comparison between the reflected waves received by the internal module and the waves received by the second external module, and
• f) in case of simultaneous detection by the internal module and by the second external module of an event, then detection of presence inside the vehicle using the reflected waves of the internal module from which the waves corresponding to the detected event are subtracted.