Method for detecting the approach of an object on a lateral side of a moving vehicle and on-board associated detection device

A method for detecting the approach of an object (V2) on a lateral side of a moving motor vehicle (V1), said vehicle (V1) being fitted with door handles (10, 20) on said lateral side, each of which includes an ultra-high-frequency antenna (BLE1, BLE2) designed, when the vehicle (V1) is stationary, to detect the presence of a portable user apparatus in the vicinity of the vehicle (V1) and to identify said apparatus in order to validate hands-free access to the vehicle (V1) for the user, said method comprising:

• the antennas (BLE1, BLE2) are initially adapted (step E0) such that each one of said antennas (BLE1, BLE2) emits an electromagnetic field, a first radiated power (P1) per steradian of which, in a first zone (Z1) oriented toward the outside of the vehicle and defined by a first aperture angle (α), is greater than a second radiated power (P2) per steradian in a second, lateral zone (Z2) directed toward the other antenna and defined by a second aperture angle (β),
• and, when the vehicle (V1) is moving, the detection (step E2) of the approach of the object (V2) is validated by the reception, by at least one antenna (BLE1, BLE2), of an electromagnetic field emitted by the other antenna (BLE1, BLE2) and reflected by the object (V2), the received power (RSSI1) of which is higher than a predetermined minimum received power (RSSIMIN) (step E1).