It is proposed a positioning assistance system for a vibrator truck, that is configured to determine a vibration point distance between the vibrator truck and the vibration point location; determine a stopping distance for stopping the vibrator truck at a vibration point location, according to a determined current speed of the vibrator truck and according to a speed profile; determine a time for stopping the vibrator truck at the vibration point location according to the current speed of the vibrator truck, when the stopping distance corresponds to said vibration point distance; and trigger the lifting down of the baseplate of the vibratory system, when at least the following condition is met: said stopping time is inferior or equal to a time for lifting down the vibratory system to the ground. Corresponding vibrator truck and method are also proposed.