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 at least one internal ultra-wideband transceiver module of waves at various predetermined frequencies and at various associated predetermined powers, and simultaneous transmission of waves by a first external ultra-wideband transceiver module of the at least two external ultra-wideband transceiver modules, the various predetermined frequencies including a first predetermined frequency and a first predetermined power value, and a second predetermined frequency and a second predetermined power value, and wherein the alternation by the at least one internal ultra-wide transceiver module of waves at the various predetermined frequencies and the various associated predetermined power includes transmission at the first predetermined frequency and the first predetermined power value, and repeated at a different frequency and power value, the different frequency and power value being at least one of the second predetermined frequency and the second predetermined power value,
• c) reception, by the at least one internal ultra-wideband transceiver module, of reflected waves,
• d) reception, by a second external ultra-wideband transceiver module of the at least two external ultra-wideband transceiver module, of waves transmitted by said first external ultra-wideband transceiver module,
• e) comparison between the reflected waves received by the at least one internal ultra-wideband transceiver module and the waves received by the second external ultra-wideband transceiver module, and
• f) in case of simultaneous detection by the at least one internal ultra-wideband transceiver module and by the second external ultra-wideband transceiver module of an event, then detection of presence inside the vehicle using the reflected waves of the at least one internal ultra-wideband transceiver module from which the waves corresponding to the detected event are subtracted.