Process for controlling at least one actuator on the basis of changes of signal transit-time of at least one ultrasonic sensor

摘要

A vehicle carries one or more ultrasonic sensors, wherein the ultrasonic sensor emits and receives ultrasonic signals depending on at least one operating condition of the vehicle. A control unit calculates, from signal transit-times of reflected ultrasonic signals, distances from objects in the surround field of the vehicle, and compares changes of signal transit-times with stored changes of signal transit-times corresponding to specific user-defined gestures. If the measured and stored transit times correlate, at least one actuator is driven to open a car door such as the tail-gate (boot, trunk). Different sensors can open different doors. The user can be recognised by a video camera, and the system only operated when the driver is near the vehicle. A radio key may also be used.